http://marspedia.org/api.php?action=feedcontributions&user=Akademy&feedformat=atomMarspedia - User contributions [en]2024-03-29T15:12:25ZUser contributionsMediaWiki 1.34.2http://marspedia.org/index.php?title=Talk:Olympus_Mons&diff=126761Talk:Olympus Mons2018-11-14T00:48:20Z<p>Akademy: Created page with "Todo: * Add Features section. ~~~~"</p>
<hr />
<div>Todo:<br />
* Add Features section. [[User:Akademy|Akademy]] ([[User talk:Akademy|talk]]) 00:48, 14 November 2018 (GMT)</div>Akademyhttp://marspedia.org/index.php?title=Olympus_Mons&diff=126760Olympus Mons2018-11-14T00:46:01Z<p>Akademy: Cleaned up refs</p>
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<div>[[Image:Olympus_Mons.jpg|thumb|right|300px|Olympus Mons as seen by [[Mars Global Surveyor]]]] <br />
'''Olympus Mons''' is a dormant [[shield volcano]] in the [[Tharsis]] region of Mars. It is easily the tallest volcano on Mars, and is believed to be the tallest in the [[Solar System]].<br />
<br />
== Location ==<br />
<br />
The volcano is located in Mars's western hemisphere at approximately 18.65 N and 226.2 E, just to the northwestern edge of the [[Tharsis Bulge]]. The western portion of the volcano lies in the [[Amazonis quadrangle]] and the central and eastern portions in the [[Tharsis quadrangle]].<br />
<br />
== Dimensions ==<br />
<br />
The top of ''Olympus Mons'' is the highest point on Mars. By one measure, it has a height of nearly 22&nbsp;km (13.6&nbsp;mi or 72,000&nbsp;ft).<ref name=Plescia04>{{cite journal | last1 = Plescia | first1 = J. B. | year = 2004 | title = Morphometric Properties of Martian Volcanoes | url = | journal = J. Geophys. Res. | volume = 109 | issue = | page = E03003 | doi = 10.1029/2002JE002031 | bibcode=2004JGRE..109.3003P}}</ref>. Olympus Mons stands about two and a half times as tall as Mount Everest's height above sea level, and is currently the largest volcano discovered in the Solar System.<br />
<br />
[[File: Olympus Mons Side View.svg.png|thumb|left|300px|Height of Olympus Mons compared tall mountains on Earth]]<br />
<br />
At 600 km (370 mi) in diameter the footprint of Olympus Mons covers an area of land comparable to the size of France.<br />
<br />
[[Image:France OlympusMons Size.svg.png|thumb|right|300px|Olympus Mons compared to the country of France]] <br />
<br />
== Age ==<br />
<br />
It is the youngest of the large volcanoes on Mars and some of the evidence from the ancient lava flows suggest a range in age from 115 million years old to 2000 million years old. This is relatively recent in comparison to most of Mars' other geology.<br />
<br />
== Composition ==<br />
<br />
=== Rock ===<br />
Much of the terrain is obscured by fine dust covering the underlying bedrock but Olympus Mons probably has the same composition to most of the dark areas on Mars which were formed by volcanic eruptions. The surface of Mars, including Olympus Mons is [[basalt]] of a type (tholeiites) similar to that of Earth's oceanic crust. This is the general conclusion drawn from Martian meteorites, analyses of soils and rocks at robotic landing sites, and information gathered with orbiting spacecraft.<ref> McSween Jr., H. Y., Taylor, G. J., and Wyatt, M. B. 2009. Elemental Composition of the Martian Crust. Science, v. 324(5928), p.736-739, doi: 10.1126/science.1165871. </ref> <ref>"Mars Crust : Made of Basalt" http://www.psrd.hawaii.edu/May09/Mars.Basaltic.Crust.html</ref><br />
<br />
Lava flows consisting of this composition would have low [[viscosity]] producing a watery flow that creates a typical shield volcanoes. Olympus Mons has a very gradual slope of, on average, only 5°.<ref>Wikipedia Olympus Mons https://en.wikipedia.org/w/index.php?title=Olympus_Mons</ref> It would be a long but very gentle climb up Olympus Mons.<br />
<br />
[[Image: 44828 2030lavaflow.jpg|thumb|right|300px|Lava flows from Olympus Mons, as seen by HiRISE]]<br />
<br />
High-altitude clouds frequently drift over the Olympus Mons summit, and airborne Martian dust is still present.<ref>Hartmann, W.K. ''A Traveler’s Guide to Mars: The Mysterious Landscapes of the Red Planet.'' Workman: New York, 2003, p. 300.</ref> <br />
The typical atmospheric pressure at the top of Olympus Mons is about 12% of the average Martian surface pressure.<ref name="stanford">[http://www-star.stanford.edu/projects/mgs/tps-public.html Public Access to Standard Temperature-Pressure Profiles]</ref> <br />
<br />
=== Ice ===<br />
As with tall mountains on the Earth, there has been much snowfall on Olympus Mons. Scientists see much evidence for glaciers.<ref name="Basilevsky, A. 2006">{{Cite journal|author=Basilevsky, A. |date=2006 |title=Geological recent tectonic, volcanic and fluvial activity on the eastern flank of the Olympus Mons volcano, Mars |journal=Geophysical Research Letters |volume=33 |issue=13 |pages=13201, L13201 |doi=10.1029/2006GL026396 | |last2=Werner |first2=S. C. |last3=Neukum |first3=G. |last4=Head |first4=J. W. |last5=Van Gasselt |first5=S. |last6=Gwinner |first6=K. |last7=Ivanov |first7=B. A. }}</ref><br />
<br />
== Exploration ==<br />
<br />
Olmypus Mons has been known to astronomers since the late 19th century as the albedo feature Nix Olympica (Latin for "Olympic Snow"). Its mountainous nature was suspected well before space probes confirmed its identity as a mountain.<ref>[[Patrick Moore]] 1977, ''Guide to Mars'', London (UK), Cutterworth Press, p. 96</ref><br />
<br />
Unfortunately Olympus Mons is an unlikely landing location for automated space probes in the near future. The high elevations preclude parachute-assisted landings because the atmosphere above is not sufficient to slow the spacecraft down before landing. Moreover, Olympus Mons stands in one of the dustiest regions of Mars. This would likely make rock samples hard to come by and the dust layer would also likely cause severe maneuvering problems for rovers.<ref>https://en.wikipedia.org/w/index.php?title=Olympus_Mons</ref><br />
<br />
== References ==<br />
<br />
<references/><br />
<br />
== See Also ==<br />
*[[Geography of Mars]]<br />
<br />
[[Category:Aerography]]<br />
[[Category:Geography]]<br />
[[category:volcano]]<br />
<br />
[[Category: Place Names]]</div>Akademyhttp://marspedia.org/index.php?title=Olympus_Mons&diff=126759Olympus Mons2018-11-14T00:29:43Z<p>Akademy: Tidied up and categorized.</p>
<hr />
<div>[[Image:Olympus_Mons.jpg|thumb|right|300px|Olympus Mons as seen by [[Mars Global Surveyor]]]] <br />
'''Olympus Mons''' is a dormant [[shield volcano]] in the [[Tharsis]] region of Mars. It is easily the tallest volcano on Mars, and is believed to be the tallest in the [[Solar System]].<br />
<br />
== Location ==<br />
<br />
The volcano is located in Mars's western hemisphere at approximately 18.65 N and 226.2 E, just to the northwestern edge of the Tharsis bulge.<ref>https://planetarynames.wr.usgs.gov/Page/MARS/target</ref> The western portion of the volcano lies in the Amazonis quadrangle and the central and eastern portions in the Tharsis quadrangle.<br />
<br />
== Dimensions ==<br />
<br />
The top of ''Olympus Mons'' is the highest point on Mars. By one measure, it has a height of nearly 22&nbsp;km (13.6&nbsp;mi or 72,000&nbsp;ft).<ref name=Plescia04>{{cite journal | last1 = Plescia | first1 = J. B. | year = 2004 | title = Morphometric Properties of Martian Volcanoes | url = | journal = J. Geophys. Res. | volume = 109 | issue = | page = E03003 | doi = 10.1029/2002JE002031 | bibcode=2004JGRE..109.3003P}}</ref>. Olympus Mons stands about two and a half times as tall as Mount Everest's height above sea level, and is currently the largest volcano discovered in the Solar System.<br />
<br />
[[File: Olympus Mons Side View.svg.png|thumb|left|300px|Height of Olympus Mons compared tall mountains on Earth]]<br />
<br />
At 600 km (370 mi) in diameter the footprint of Olympus Mons covers an area of land comparable to the size of France.<br />
<br />
[[Image:France OlympusMons Size.svg.png|thumb|right|300px|Olympus Mons compared to the country of France]] <br />
<br />
== Age ==<br />
<br />
It is the youngest of the large volcanoes on Mars and some of the evidence from the ancient lava flows suggest a range in age from 115 million years old to 2000 million years old. This is relatively recent in comparison to most of Mars' other geology.<br />
<br />
== Composition ==<br />
<br />
=== Rock ===<br />
Much of the terrain is obscured by fine dust covering the underlying bedrock but Olympus Mons probably has the same composition to most of the dark areas on Mars which were formed by volcanic eruptions. The surface of Mars, including Olympus Mons is basalt of a type (tholeiites) similar to that of Earth's oceanic crust. This is the general conclusion drawn from Martian meteorites, analyses of soils and rocks at robotic landing sites, and information gathered with orbiting spacecraft.<ref> McSween Jr., H. Y., Taylor, G. J., and Wyatt, M. B. 2009. Elemental Composition of the Martian Crust. Science, v. 324(5928), p.736-739, doi: 10.1126/science.1165871. </ref> <ref>http://www.psrd.hawaii.edu/May09/Mars.Basaltic.Crust.html</ref><br />
<br />
Lava flows of this composition would have displayed low viscosity - a watery flow that produces typical shield volcanoes with a very gradual slope.<ref>https://en.wikipedia.org/w/index.php?title=Olympus_Mons&action=edit&section=1</ref><br />
<br />
[[Image: 44828 2030lavaflow.jpg|thumb|right|300px|Lava flows from Olympus Mons, as seen by HiRISE]]<br />
<br />
High-altitude clouds frequently drift over the Olympus Mons summit, and airborne Martian dust is still present.<ref>Hartmann, W.K. ''A Traveler’s Guide to Mars: The Mysterious Landscapes of the Red Planet.'' Workman: New York, 2003, p. 300.</ref> <br />
The typical atmospheric pressure at the top of Olympus Mons is about 12% of the average Martian surface pressure.<ref name="stanford">[http://www-star.stanford.edu/projects/mgs/tps-public.html Public Access to Standard Temperature-Pressure Profiles]</ref> <br />
<br />
=== Ice ===<br />
As with tall mountains on the Earth, there has been much snowfall on Olympus Mons. Scientists see much evidence for glaciers.<ref name="Basilevsky, A. 2006">{{Cite journal|author=Basilevsky, A. |date=2006 |title=Geological recent tectonic, volcanic and fluvial activity on the eastern flank of the Olympus Mons volcano, Mars |journal=Geophysical Research Letters |volume=33 |issue=13 |pages=13201, L13201 |doi=10.1029/2006GL026396 | |last2=Werner |first2=S. C. |last3=Neukum |first3=G. |last4=Head |first4=J. W. |last5=Van Gasselt |first5=S. |last6=Gwinner |first6=K. |last7=Ivanov |first7=B. A. }}</ref><br />
<br />
== Exploration ==<br />
<br />
Olmypus Mons has been known to astronomers since the late 19th century as the albedo feature Nix Olympica (Latin for "Olympic Snow"). Its mountainous nature was suspected well before space probes confirmed its identity as a mountain.<ref>[[Patrick Moore]] 1977, ''Guide to Mars'', London (UK), Cutterworth Press, p. 96</ref><br />
<br />
Unfortunately Olympus Mons is an unlikely landing location for automated space probes in the near future. The high elevations preclude parachute-assisted landings because the atmosphere above is not sufficient to slow the spacecraft down before landing. Moreover, Olympus Mons stands in one of the dustiest regions of Mars. This would likely make rock samples hard to come by and the dust layer would also likely cause severe maneuvering problems for rovers.<ref>https://en.wikipedia.org/w/index.php?title=Olympus_Mons&action=edit&section=1</ref><br />
<br />
== References ==<br />
<br />
<references/><br />
<br />
== See Also ==<br />
*[[Geography of Mars]]<br />
<br />
[[Category:Aerography]]<br />
[[Category:Geography]]<br />
[[category:volcano]]<br />
<br />
[[Category: Place Names]]</div>Akademyhttp://marspedia.org/index.php?title=Astronomical_Unit&diff=126758Astronomical Unit2018-11-13T23:42:57Z<p>Akademy: </p>
<hr />
<div>An '''Astronomical Unit''' (AU) is most often used to measure distances within the Solar System. One astronomical unit is approximately the distance between the Earth and the Sun but is defined as exactly 150 million km (150'000'000 km).<br />
<br />
For example Mars is about 2.5 AU from the Sun, which means it is 2.5 times the distance from the Earth to the Sun, or approximately 375 million km from the Sun (i.e. 150'000'000 km * 2.5).<br />
<br />
<br />
{{stub}}</div>Akademyhttp://marspedia.org/index.php?title=Solar_System&diff=126757Solar System2018-11-13T23:15:09Z<p>Akademy: Extended information.</p>
<hr />
<div>The '''Solar System''' refers specifically to our Sun's star system. A star system is the area around a star containing bodies which orbit that star. The Solar System consists of the terrestrial planets, the gas giants, moons, dwarf planets, asteroids, comets, and vast amounts of dust and debris. Also, Mars.<br />
<br />
== Orbital Bodies ==<br />
<br />
The Solar System mostly consists of the [[vacuum]] of space, but there are many countless bodies out amongst it.<br />
<br />
=== Sun ===<br />
At the heart of our '''Solar System''' is our star the [[Sun]]. It is by far the most massive object in the Solar System, and is why all other bodies in the solar system orbit it. <br />
<br />
The Sun is constantly sending out Solar energy in the form of radiation and charged particles, a minor percentage of which intersects with the bodies across the Solar System.<br />
<br />
=== Major Planets ===<br />
The Sun has many bodies orbiting and gravitationally bound to it, but the most significant of these bodies are the eight major planets. These include the terrestrial planets [[Mercury]], [[Venus]], [[Earth]], [[Mars]] and the gas giants [[Jupiter]], [[Saturn]], [[Uranus]] and [[Neptune]] (although there are several moons larger than Mercury).<br />
<br />
The terrestrial planets are mostly composed of rock but with a thin atmosphere of gas. The gas giants are the biggest objects in the Solar System, after the Sun and are almost entirely composed of a thick gaseous atmosphere around a small solid body.<br />
<br />
All of the planets orbit in the same plain of the Solar System as each other.<br />
<br />
=== Dwarf Planets ===<br />
The next biggest objects in the Solar System are the [[Dwarf Planets]]. [[Pluto]] is the most well known of the dwarf planets and orbits out at around 40 [[Astronomical Unit|AU]], but many others exist throughout the solar system, including [[Ceres]] in the asteroid belt at 2.7 AU just beyond Mars' orbit, and [[Eris]] orbiting well beyond Pluto out at 67 AU.<br />
<br />
Many of the dwarf planets, orbit in their own unique plain, above or below the plain that contains the planets.<br />
<br />
=== Moons / Satellites ===<br />
Many of the largest bodies in the Solar System are actually moons orbiting the major planets. ''The Moon'' which orbits Earth is one of the largest in the Solar System, but the biggest moon in the Solar System is Ganymede which orbits around Jupiter. This has a diameter of 5,268 km and is actually larger than the planet Mercury.<br />
<br />
There are also many moons which orbit around dwarf planets and other minor bodies. These are often comparable in size to the objects they orbit.<br />
<br />
The planet Mars has two very small moons called Phobos and Deimos. But both of these are thought to be captured asteroids which at some point passed close enough to Mars to be captured by its gravity.<br />
<br />
=== Asteroid Belt and asteroids ===<br />
The ''[[Asteroid Belt]]'' exists between the orbits of Mars and Jupiter and consists of many small rocky bodies (i.e [[asteroids]]) of different shapes and sizes. However, collisions between objects are quite rare because the distances between objects are quite large.<br />
<br />
Although there are many individual asteroids, the total mass of all the objects in the Asteroid Belt is not even thought to exceed the mass of the dwarf planet Pluto. It is believed Jupiters influence on the asteroids is the reason they have never coalesced into a single body.<br />
<br />
The asteroids in the Asteroid Belt all orbit on the same plain as the major planets. <br />
<br />
=== Kuiper Belt and comets ===<br />
<br />
The ''[[Kuiper Belt]]'' consists of many, many cold, icy bodies as the distance from the Sun means they receive very little radiation.<br />
<br />
Occasionally these objects will be perturbed in someway and their trajectory will change enough so that they enter the inner solar system. These objects are known as [[comets]] and iconic "tail" is produced as they get closer to the sun, heat up and break up.<br />
<br />
=== Oort Cloud ===<br />
<br />
At the edge of the solar system, exists the Oort Cloud. Unlike other objects in the Solar System which orbit in a single plain the objects in the Oort cloud completely surround the Solar System.<br />
<br />
== Size ==<br />
<br />
The edge of the Solar System is difficult to detect but has been defined as the point where the Sun's influence ends. This is the point where the Sun's solar wind equals that of the background value of our galaxy. <br />
<br />
The extend of the Solar System is calculated to be at around 120 AU.<br />
<br />
== Creation ==<br />
<br />
The Solar System is thought to have been created from the collapse of a massive gas cloud. The Sun first capturing most of the mass and triggering the creation of the other bodies through countless collisions.<br />
<br />
The collapse of the gas cloud and the startof the Solar system is believed to have happened around 4.6 billion years ago.<br />
<br />
[[Category: Astronomy]]</div>Akademyhttp://marspedia.org/index.php?title=Astronomical_Unit&diff=126756Astronomical Unit2018-11-13T22:08:43Z<p>Akademy: Quick definition</p>
<hr />
<div>{{stub}}<br />
<br />
An '''Astronomical Unit''' (AU) is most often used to measure distances within the Solar System. One astronomical unit is approximately the distance between the Earth and the Sun but is defined as exactly 150 million km (150'000'000 km).<br />
<br />
For example Mars is about 2.5 AU from the Sun, which means it is 2.5 times the distance from the Earth to the Sun, or approximately 375 million km from the Sun (i.e. 150'000'000 km * 2.5).</div>Akademyhttp://marspedia.org/index.php?title=Olympus_Mons&diff=126755Olympus Mons2018-11-13T20:28:48Z<p>Akademy: Trying to fix positioning on mobile.</p>
<hr />
<div>'''Olympus Mons''' is a dormant [[shield volcano|shield]] [[volcano]] in the [[Tharsis]] region. It is the highest point on Mars. By one measure, it has a height of nearly 22&nbsp;km (13.6&nbsp;mi or 72,000&nbsp;ft).<ref name=Plescia04>{{cite journal | last1 = Plescia | first1 = J. B. | year = 2004 | title = Morphometric Properties of Martian Volcanoes | url = | journal = J. Geophys. Res. | volume = 109 | issue = | page = E03003 | doi = 10.1029/2002JE002031 | bibcode=2004JGRE..109.3003P}}</ref> Olympus Mons<br />
stands about two and a half times as tall as Mount Everest's height above sea level. It is the youngest of the large volcanoes on Mars. It is currently the largest volcano discovered in the Solar System and had been known to astronomers since the late 19th century as the albedo feature Nix Olympica (Latin for "Olympic Snow"). Its mountainous nature was suspected well before space probes confirmed its identity as a mountain.<ref>[[Patrick Moore]] 1977, ''Guide to Mars'', London (UK), Cutterworth Press, p. 96</ref><br />
<br />
[[File: Olympus Mons Side View.svg.png|thumb|left|300px|Height of Olympus Mons compared tall mountains on Earth]] <br />
<br />
<br />
[[Image:France OlympusMons Size.svg.png|thumb|right|300px|Olympus Mons compared to the country of France]] <br />
<br />
The volcano is located in Mars's western hemisphere at approximately 18.65 N and 226.2 E, just to the northwestern edge of the Tharsis bulge.<ref>https://planetarynames.wr.usgs.gov/Page/MARS/target</ref> The western portion of the volcano lies in the Amazonis quadrangle and the central and eastern portions in the Tharsis quadrangle.<br />
<br />
Olympus Mons probably has the same composition to most of the dark areas on Mars. These dark areas were formed by volcanic eruptions. The surface of Mars, including Olympus Mons is basalt of a type (tholeiites) similar to that of Earth's oceanic crust. This is the general conclusion drawn from Martian meteorites, analyses of soils and rocks at robotic landing sites, and information gathered with orbiting spacecraft.<ref> McSween Jr., H. Y., Taylor, G. J., and Wyatt, M. B. 2009. Elemental Composition of the Martian Crust. Science, v. 324(5928), p.736-739, doi: 10.1126/science.1165871. </ref> <ref>http://www.psrd.hawaii.edu/May09/Mars.Basaltic.Crust.html</ref><br />
<br />
Lava flows of this composition would have displayed low viscosity, a watery flow that would have produced a volcano with a very gradual slope.<ref>https://en.wikipedia.org/w/index.php?title=Olympus_Mons&action=edit&section=1</ref><br />
<br />
High-altitude clouds frequently drift over the Olympus Mons summit, and airborne Martian dust is still present.<ref>Hartmann, W.K. ''A Traveler’s Guide to Mars: The Mysterious Landscapes of the Red Planet.'' Workman: New York, 2003, p. 300.</ref> <br />
The typical atmospheric pressure at the top of Olympus Mons is about 12% of the average Martian surface pressure.<ref name="stanford">[http://www-star.stanford.edu/projects/mgs/tps-public.html Public Access to Standard Temperature-Pressure Profiles]</ref> <br />
Olympus Mons is an unlikely landing location for automated space probes in the near future. The high elevations preclude parachute-assisted landings because of insufficient atmospheric thickness to slow the spacecraft down. Moreover, Olympus Mons stands in one of the dustiest regions of Mars. A mantle of fine dust covers much of the terrain, obscuring the underlying bedrock and possibly making rock samples hard to come by. The dust layer would also likely cause severe maneuvering problems for rovers.<ref>https://en.wikipedia.org/w/index.php?title=Olympus_Mons&action=edit&section=1</ref><br />
<br />
As with tall mountains on the Earth, there has been much snowfall on Olympus Mons. Scientists see much evidence for glaciers.<ref name="Basilevsky, A. 2006">{{Cite journal|author=Basilevsky, A. |date=2006 |title=Geological recent tectonic, volcanic and fluvial activity on the eastern flank of the Olympus Mons volcano, Mars |journal=Geophysical Research Letters |volume=33 |issue=13 |pages=13201, L13201 |doi=10.1029/2006GL026396 | |last2=Werner |first2=S. C. |last3=Neukum |first3=G. |last4=Head |first4=J. W. |last5=Van Gasselt |first5=S. |last6=Gwinner |first6=K. |last7=Ivanov |first7=B. A. }}</ref><br />
<br />
<br />
[[Image:Olympus_Mons.jpg|thumb|right|300px|Olympus Mons as seen by [[Mars Global Surveyor]]]] <br />
[[Image: 44828 2030lavaflow.jpg|thumb|right|300px|Lava flows from Olympus Mons, as seen by HiRISE]]<br />
<br/><!-- Clear to allow text to flow after images aligned --><br />
<br />
==References:==<br />
<references/><br />
<br />
==See Also==<br />
*[[Geography of Mars]]<br />
<br />
{{stub}}<br />
[[Category:Aerography]]<br />
[[Category:Geography]]<br />
[[category:volcano]]<br />
<br />
[[Category: Place Names]]</div>Akademyhttp://marspedia.org/index.php?title=Marspedia:Sandbox&diff=126754Marspedia:Sandbox2018-11-13T20:17:49Z<p>Akademy: test clear</p>
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==This ought to go somewhere besides here==<br />
My son made a Mars school project that was very thorough and worth sharing. He crafted his project based on a three step development process. Spaceships from Earth, both unmanned round rocket supply ships carrying food, Oxygen and Hydrogen, as well as Nuclear Photogenic reactors, would be send to Mars in conjunction with manned space shuttle spaceships that woudl carry space engineers (not scientists!), to stay on Mars for the sole purpose to setup the Nuclear Photogenic reactors for electricity/heat/CO2 converter, and to dig the trenches to put the temporary living quarters, and also build the initial clear plastic domes (lightweight) to house the future biotanical garden. The space engineers would then leave for another Mars colony construction site or rotate back to Earth and then the initial colonists would arrive to take up the next step of the colony. The colonists would construct/maintain the living quarters, plant vegatation, install distilory machines (all the ingredients to make alcohol on Mars!, for export/antiseptic/fuel/etc.) and also start deep mining activity to build future habitation below the surface (for the ultraviolet radiation is not blocked by Mars atmosphere, infrared is blocked by Carbon Dioxide). Steel production on Mars would also be a big export since Steel is 99% Iron and 1% carbon, which Mars has abundance of. The Nuclear photovoltic engines would provide the heat and electrical energy to support all the colonies power/heat needs. The colonists would also build pressurized containers to store fresh water, waste water, alcohol, ammonia, and compressed air such as methane, carbon dioxide, hydrogen, oxygen, and other medical needs such as nitrous oxide, hydrogen sulfide, etc. Recycling everything from water/kitchen/human waste is essential, and new biotanical gardens will be planted to expediate the conversion of waste back into reusable water/top soil. Supporting the biotanical gardens and creating new garden domes will be a life long career. Building tunnals below the surface will also be a career duty on Mars (reminds me of the movie "Total Recall". Once the colony is sustainable without need for resupply ships from Earth, then Mars can also function as a penial colony for the dual purpose to put hardened criminals to good use working to improve Mars as well as alleviating the population epidemic on Earth. Mars will then focus on its role as space port for exploration/colonization of Jupitor and Saturn moons.<br />
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== Captcha Test ==<br />
Marspedia has some sister sites, a general space wiki at '''[http://exoplatz.org Exoplatz]''', a space dictionary at '''[http://exodictionary.org Exodictionary]''', a Moon wiki at '''[http://lunarpedia.org Lunarpedia]''', and scientific fiction at '''[http://scientifiction.org Scientifiction.org]'''.<br />
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Some text at the start of the section. Then images:<br />
[[Image:Olympus_Mons.jpg|thumb|right|300px|Olympus Mons as seen by [[Mars Global Surveyor]]]] <br />
[[Image: 44828 2030lavaflow.jpg|thumb|right|300px|Lava flows from Olympus Mons, as seen by HiRISE]]<br />
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Should now be "cleared"</div>Akademyhttp://marspedia.org/index.php?title=Asteroids&diff=126753Asteroids2018-11-13T20:07:53Z<p>Akademy: Added stub</p>
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[[Image:Asteroids.png|thumb|right|300px|The distribution of '''asteroids''' in the inner Solar System.]]<br />
'''Asteroids''', also known as ''minor planets'' or ''planetoids'', are significantly-sized debris that orbit the [[Sun]]. The ''Asteroid Belt'' can be found between the orbits of [[Mars]] and [[Jupiter]], making up the majority of the population of asteroids in the inner Solar System. Groups of asteroids also swarm around the fourth and fifth [[Lagrangian point]]s (<math>L_4</math> and <math>L_5</math>) of Jupiter and are known as the ''Greeks'' and the ''Trojans'' respectively. Jupiter's [[Lagrangian point]] asteroids are generally known as ''Trojan asteroids'', and this term is often used to describe Mars' Lagrangian objects. The ''Hildas'' are another swarm of asteroids on the far-side of the Sun (opposing Jupiter). The ''Hildas'' are in orbital resonance with the large gas giant and can be found near Jupiter's <math>L_3</math> point.<br />
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[[category:Orbital Mechanics]]</div>Akademyhttp://marspedia.org/index.php?title=Dark_slope_streaks&diff=126252Dark slope streaks2018-09-23T17:43:57Z<p>Akademy: Improve formatting</p>
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<div>[[File:Fan-shaped Streaks ESP 012410 1835cropped.jpg|300px|right|Dark slope streaks, as seen by HiRISE]]<br />
Dark slope streaks are found on Mars on dust-covered slopes often near the equator, they are believed to be avalanches involving darker martian dust.<br />
<br />
==Appearance==<br />
<br />
Dark slope streaks are found on dust-covered slopes, particular near the equator.<ref name="Chuang10">Chuang, F.C.; Beyer, R.A.; Bridges, N.T. (2010). Modification of Martian Slope Streaks by Eolian Processes. ''Icarus,'' '''205''' 154–164.</ref> <br />
<br />
The streaks start out only about 10% darker than their surrounds <ref>Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref> (This is confused because many images of the streaks have been post-processed to bring out more detail and appear much darker). Over time these streaks tend to get lighter as the brighter Martian dust settles from the atmosphere. The darker ones are the newest.<br />
<br />
Typically, streaks begin at a small point high on a steep slope, such as a crater wall.<ref name="Schorghofer02">Schorghofer, N.; Aharonson, O.; Khatiwala, S. 2002. Slope Streaks on Mars: Correlations with Surface Properties and the Potential Role of Water. ''Geophys. Res. Lett.,'' '''29'''(23), 2126.</ref> And then they greatly widen and sometimes divide into finger-like extensions (digitation). Obstacles, such as boulders, may cause an individual streak to split into two separate streaks or eventually form a braided (anastomosing) pattern.<ref>Chuang, F.C. et al. 2007. HiRISE Observations of Slope Streaks on Mars. Geophys. Res. Lett., 34 L20204.</ref> Many have a fan shape. <ref>Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<br />
Streaks may be hundreds of meters long with a width of 20 to 200 meters. Indeed, some can be over 2 kilometers long. <br />
<ref>Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<ref>Chuang, F.C.; Beyer, R.A.; Bridges, N.T. 2010. Modification of Martian Slope Streaks by Eolian Processes. Icarus, 205 154–164.</ref><br />
<ref>Baratoux, D. et al. 2006. The Role of the Wind-Transported Dust in Slope Streaks Activity: Evidence from the HRSC Data. Icarus, 183 30–45.</ref><br />
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<gallery class="center" widths="190px" heights="180px"><br />
File:PIA22240slopstreaks.jpg | Close view of dark slope streaks<br />
File:55107 1930streaksclose.jpg|Streak being affected by boulders. Arrows indicate boulders and resulting effect on streak.<br />
File:55480 2060streaksobstacles.jpg|Close view of streak showing boulders causing streak to divide<br />
</gallery><br />
<br />
==How long do they last?==<br />
Thanks to the many excellent cameras that we have placed in orbit over many decades, we have a history of how the Martian surface changes. Dark slope streaks are some of the most changing parts of Mars. They were discovered in Viking Orbiter pictures from the 1970,<ref name="Morris82">Morris, E.C. (1982). Aureole Deposits of the Martian Volcano Olympus Mons. ''J. Geophys. Res.,'' '''87'''(B2), 1164–1178.</ref> <ref name="Ferguson84">Ferguson,H.M.; Lucchitta, B.K. (1984). Dark Streaks on Talus Slopes, Mars in ''Reports of the Planetary Geology Program 1983, NASA Tech. Memo., TM-86246,'' pp. 188–190. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840015363_1984015363.pdf.</ref> When images from Mars Global Surveyor (MGS) and Mars Reconnaissance Orbiter (MRO) spacecraft are examined, the life history of streaks can be precisely determined.<ref>Sullivan, R. et al. (2001). Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633. </ref> <ref name="Chuang07">Chuang, F.C. et al. 2007. HiRISE Observations of Slope Streaks on Mars. 'Geophys. Res. Lett. 34 L20204.</ref> <ref>Dundas, C. 2018. HIRISE OBSERVATIONS OF NEW MARTIAN SLOPE STREAKS. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2026.pdf</ref> <ref>Malin, M.C.; Edgett, K.S. (2001). Mars Global Surveyor Mars Orbiter Camera: Interplanetary cruise through primary mission. J. Geophys. Res., 106(E10), 23,429–23,570.</ref> <ref>Edgett, K.S.; Malin, M.C.; Sullivan, R.J.; Thomas, P.; Veverka, J. (2000). Dynamic Mars: New Dark Slope Streaks Observed on Annual and Decadal Time Scales. 31st Lunar and Planetary Science Conference, Abstract #1058. http://www.lpi.usra.edu/meetings/lpsc2000/pdf/1058.pdf.</ref><br />
<br />
One analysis concluded that 70 streaks per day may form on the planet. The research team compared overlapping images from Mars Global Surveyor Mars Orbiter Camera that were spaced days to years apart. <ref>Aharonson, O.; Schorghofer, N.; Gerstell, M.F. (2003). Slope Streak Formation and Dust Deposition Rates on Mars. J. Geophys. Res., 108(E12), 5138, doi:10.1029/2003JE002123. </ref><br />
Dark slope streaks are constantly forming and fading. The darker ones are the youngest. Fading is accomplished by settling of bright dust in the Martian atmosphere. When researches looked at a small area (Lycus Sulci) on Mars with both Viking images and recent CTX images from the Mars Reconnaissance Orbiter, they found that the ones seen in Viking photos were gone, however, new streaks have taken their place. Their calculations indicated that slope streaks last about 40 years <ref>Bergonio, J., K. Rottas, and N. Schorghofer. 2013. Properties of martian slope streak populations: 225. Icarus: 194-199.</ref><br />
<br />
It is believed that during Mar's [[global dust storm|global dust storms]] many - perhaps most - streaks and other features are erased during these occosional occurences.<ref>Aharonson, O.; Schorghofer, N.; Gerstell, M.F. 2003. S lope Streak Formation and Dust Deposition Rates on Mars. J. Geophys. Res., 108(E12), 5138, doi:10.1029/2003JE002123.</ref> <ref>Schorghofer, Aharonson, O.; Gerstell, M.F.; Tatsumi, L. 2007. Three Decades of Slope Streak Activity on Mars. Icarus: 191, 132–140. doi:10.1016/j.icarus.2007.04.026.</ref><br />
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<gallery class="center" widths="190px" heights="180px"><br />
File:New Streaks Formed PIA02379.jpg|New slope streaks formed near Apollinaris Mons between February 1998 and November 1999, as seen by Mars Orbital Camera (MOC).<br />
File:23677streakslabeled.jpg|Young and old dark slope streaks with origins labeled.<br />
</gallery><br />
<br />
==What causes dark slope streaks?==<br />
Although many ideas have been put forward to explain slope streaks, the general opinion today is that they are simply avalanches of darker colored dust.<ref>Treiman, A.H.; Louge, M.Y. (2004). Martian Slope Streaks and Gullies: Origins as Dry Granular Flows. 35th Lunar and Planetary Science Conference, Abstract #1323. http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1323.pdf</ref> Nearly all of Mars is covered with a thin, bright dust. On steep slopes this layer of dust can move away and reveal a dark surface. The dark volcanic rock basalt lies under the lighter-toned dust which falls out of the atmosphere.<br />
With the long term observations from orbit, researchers have noticed that strikes by meteorites can start the process of slope formation.<ref>http://www.uahirise.org/epo/nuggets/dust-avalanche.pdf</ref> <ref>https://hirise.lpl.arizona.edu/ESP_054066_1920</ref> Moreover, even the air blast from an oncoming strike can trigger clusters of slopes to form.<ref>Kaylan J. Burleigh, Henry J. Melosh, Livio L. Tornabene, Boris Ivanov, Alfred S. McEwen, Ingrid J. Daubar. 2012. Impact air blast triggers dust avalanches on Mars Icarus: 217 (1) 194 doi:10.1016/j.icarus.2011.10.026</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:ESP 054066 1920newstreak.jpg|New dark slope streak that was triggered by an impact Location is the Arabia quadrangle<br />
</gallery><br />
<br />
==Other slope features==<br />
<br />
Several features are common on slopes on Mars. The surface of Mars is billions of years old in most <br />
places. Consequently, it has accumulated many steep slopes, especially in craters and canyons. Although streaks, gullies, and recurring slope lineae all occur on slopes, they have different origins. <br />
[[Martian gullies]] show up in certain zones. However, unlike dark slope streaks they go fairly deep into the surface and are not erased by falling dust over time. Their origin is still debated. For over a decade they were believed to be formed by recent, flowing water. <br />
<ref>Malin, M.; Edgett, K. (2000). "Evidence for recent groundwater seepage and surface runoff on Mars". Science. 288: 2330–2335.</ref><br />
<ref>Luu, K., et al. 2018. GULLY FORMATION ON THE NORTHWESTERN SLOPE OF PALIKIR CRATER, MARS 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2650.pdf</ref> <br />
<ref>Hamid, S., V. Gulick. 2018. GEOMORPHOLOGICAL ANALYSIS OF GULLIES ALONG WESTERN SLOPES OF PALIKIR CRATER. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2644.pdf</ref> <br />
<ref>Tyler Paladin, T., et al. 2018. INSIGHTS INTO THE FORMATION OF GULLIES IN ASIMOV CRATER, MARS. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2889.pdf</ref> Now, new observations suggest that gullies are being made today by chunks of dry ice moving down steep slopes in the spring. <br />
<ref>Dundas, C., S. Diniega, A. McEwen. 2015. Long-term monitoring of martian gully formation and evolution with MRO/HiRISE. Icarus: 251, 244–263</ref> <br />
<ref>Fergason, R., C. Dundas, R. Anderson. 2015. IN-DEPTH REGIONAL ASSESSMENT OF THERMOPHYSICAL PROPERTIES OF ACTIVE GULLIES ON MARS. 46th Lunar and Planetary Science Conference. 2009.pdf</ref> <br />
<ref>Dundas, C. et al. 2016. HOW WET IS RECENT MARS? INSIGHTS FROM GULLIES AND RSL. 47th Lunar and Planetary Science Conference (2016) 2327.pdf. </ref> <br />
<ref>Vincendon, M. 2015. Identification of Mars gully activity<br />
types associated with ice composition.JGR:120, 1859–1879. </ref> <br />
<ref>Raack, J.; et al. (2015). "Present-day seasonal gully activity in a south polar pit (Sisyphi Cavi) on Mars". Icarus. 251: 226–243. Bibcode:2015Icar..251..226R. doi:10.1016/j.icarus.2014.03.040. </ref> <br />
<ref>http://www.uahirise.org/ESP_044327_1375</ref> <br />
<ref>C. Pilorget, C., F. Forget. 2015. "CO2 Driven Formation of Gullies on Mars." 46th Lunar and Planetary Science Conference. 2471.pdf</ref> <br />
<ref>Pilorget, C.; Forget, F. (2016). "Formation of gullies on Mars by debris flows triggered by CO2 sublimation". Nature Geoscience. 9: 65–69. Bibcode:2016NatGe...9...65P. </ref> <br />
<br />
Gullies and streaks are found in different areas on the planet. While the streaks are towards the equator, gullies are often found in the middle northern and southern hemispheres.<br />
<br />
Like gullies and streaks, recurring slope lineae are seen on steep slopes, but they are smaller, more narrow, and straighter. Since they seem to lengthen as the temperature increases, they were believed to be involved with liquid water.<br />
<ref>McEwen, A. et al. 2011. Seasonal Flows on Warm Martian Slopes. Science, 333(6043), 740–743. doi:10.1126/science.1204816 PMID 21817049. http://www.sciencemag.org/content/333/6043/740. </ref> <br />
<ref>Mann, Adam (18 February 2014). "Strange Dark Streaks on Mars Get More and More Mysterious". Wired. Retrieved 18 February 2014. </ref> <br />
<ref>Chang, K. 2011. "Scientists Find Signs Water Is Flowing on Mars," New York Times, August 4, A13. https://www.nytimes.com/2011/08/05/science/space/05mars.html?_r=1&ref=marsplanet. </ref> <br />
<ref>HiRISE website. Seasonal Flows on Warm Martian Slopes. http://hirise.lpl.arizona.edu/sim/science-2011-aug-4.php. </ref> <br />
<ref>McEwen, A. Ojha L.; Dundas C.; Mattson, S.; Byrne S.; Wray J.; Cull S.; Murchie S. 2011. Transient Slope Lineae: Evidence for Summertime Briny Flows on Mars? 42nd Lunar and Planetary Science Conference, Abstract #2314. http://www.lpi.usra.edu/meetings/lpsc2011/pdf/2314.pdf. </ref> <br />
Nevertheless, later studies showed that very little water, if any, could be involved.<ref>Dundas, C., et al. 2017. Granular Flows at Recurring Slope Lineae on Mars Indicate a Limited Role for Liquid Water. Nature Geoscience. Nov. 20. [1].</ref> <ref>Schaefer, E., et al. 2018. A case study of recurring slope lineae (RSL) at Tivat crater: Implications for RSL origins. Icarus: In press. https://doi.org/10.1016/j.icarus.2018.07.014</ref><br />
<br />
<gallery class="center" widths="190px" heights="180px"><br />
File:50858 1435gullies.jpg|Image of gullies with the parts "alcove", "channel", and "apron" labelled. Picture was taken by HiRISE under HiWish program.<br />
File:Streak Locations PIA09030.jpg|Map showing locations of gullies (brown) and streaks (pink)<br />
File:Oblique View of Warm Season Flows in Newton Crater.jpg|Recurrent slope lineae, as seen by HiRISE<br />
</gallery><br />
<br />
==References==<br />
{{reflist}}<br />
<br />
==See also==<br />
<br />
*[[Martian gullies]]<br />
*[[What Mars Actually Looks Like! ]]<br />
<br />
==External links==<br />
<br />
*[[yt:_sUUKcZaTgA|Martian Ice - Jim Secosky - 16th Annual International Mars Society Convention]]</div>Akademyhttp://marspedia.org/index.php?title=Dark_slope_streaks&diff=126251Dark slope streaks2018-09-23T17:30:52Z<p>Akademy: Improved image display.</p>
<hr />
<div>[[File:Fan-shaped Streaks ESP 012410 1835cropped.jpg|300px|right|Dark slope streaks, as seen by HiRISE]]<br />
Dark slope streaks are found on Mars on dust-covered slopes often near the equator, they are believed to be avalanches involving darker martian dust.<br />
<br />
==Appearance==<br />
<br />
Dark slope streaks are found on dust-covered slopes, particular near the equator.<ref name="Chuang10">Chuang, F.C.; Beyer, R.A.; Bridges, N.T. (2010). Modification of Martian Slope Streaks by Eolian Processes. ''Icarus,'' '''205''' 154–164.</ref> <br />
<br />
The streaks start out only about 10% darker than their surrounds <ref>Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref> (This is confused because many images of the streaks have been post-processed to bring out more detail and appear much darker). Over time these streaks tend to get lighter as the brighter Martian dust settles from the atmosphere. The darker ones are the newest.<br />
<br />
Typically, streaks begin at a small point high on a steep slope, such as a crater wall.<ref name="Schorghofer02">Schorghofer, N.; Aharonson, O.; Khatiwala, S. 2002. Slope Streaks on Mars: Correlations with Surface Properties and the Potential Role of Water. ''Geophys. Res. Lett.,'' '''29'''(23), 2126.</ref> And then they greatly widen and sometimes divide into finger-like extensions (digitation). Obstacles, such as boulders, may cause an individual streak to split into two separate streaks or eventually form a braided (anastomosing) pattern.<ref>Chuang, F.C. et al. 2007. HiRISE Observations of Slope Streaks on Mars. Geophys. Res. Lett., 34 L20204.</ref> Many have a fan shape. <ref>Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<br />
Streaks may be hundreds of meters long with a width of 20 to 200 meters. Indeed, some can be over 2 kilometers long. <br />
<ref>Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<ref>Chuang, F.C.; Beyer, R.A.; Bridges, N.T. 2010. Modification of Martian Slope Streaks by Eolian Processes. Icarus, 205 154–164.</ref><br />
<ref>Baratoux, D. et al. 2006. The Role of the Wind-Transported Dust in Slope Streaks Activity: Evidence from the HRSC Data. Icarus, 183 30–45.</ref><br />
<br />
<gallery class="center" widths="190px" heights="180px"><br />
File:PIA22240slopstreaks.jpg | Close view of dark slope streaks<br />
File:55107 1930streaksclose.jpg|Streak being affected by boulders. Arrows indicate boulders and resulting effect on streak.<br />
File:55480 2060streaksobstacles.jpg|Close view of streak showing boulders causing streak to divide<br />
</gallery><br />
<br />
==How long do they last?==<br />
Thanks to the many excellent cameras that we have placed in orbit over many decades, we have a history of how the Martian surface changes. Dark slope streaks are some of the most changing parts of Mars. They were discovered in Viking Orbiter pictures from the 1970,<ref name="Morris82">Morris, E.C. (1982). Aureole Deposits of the Martian Volcano Olympus Mons. ''J. Geophys. Res.,'' '''87'''(B2), 1164–1178.</ref> <ref name="Ferguson84">Ferguson,H.M.; Lucchitta, B.K. (1984). Dark Streaks on Talus Slopes, Mars in ''Reports of the Planetary Geology Program 1983, NASA Tech. Memo., TM-86246,'' pp. 188–190. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840015363_1984015363.pdf.</ref> When images from Mars Global Surveyor (MGS) and Mars Reconnaissance Orbiter (MRO) spacecraft are examined, the life history of streaks can be precisely determined.<ref>Sullivan, R. et al. (2001). Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633. </ref> <ref name="Chuang07">Chuang, F.C. et al. 2007. HiRISE Observations of Slope Streaks on Mars. 'Geophys. Res. Lett. 34 L20204.</ref> <ref>Dundas, C. 2018. HIRISE OBSERVATIONS OF NEW MARTIAN SLOPE STREAKS. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2026.pdf</ref> <ref>Malin, M.C.; Edgett, K.S. (2001). Mars Global Surveyor Mars Orbiter Camera: Interplanetary cruise through primary mission. J. Geophys. Res., 106(E10), 23,429–23,570.</ref> <ref>Edgett, K.S.; Malin, M.C.; Sullivan, R.J.; Thomas, P.; Veverka, J. (2000). Dynamic Mars: New Dark Slope Streaks Observed on Annual and Decadal Time Scales. 31st Lunar and Planetary Science Conference, Abstract #1058. http://www.lpi.usra.edu/meetings/lpsc2000/pdf/1058.pdf.</ref><br />
<br />
One analysis concluded that 70 streaks per day may form on the planet. The research team compared overlapping images from Mars Global Surveyor Mars Orbiter Camera that were spaced days to years apart. <ref>Aharonson, O.; Schorghofer, N.; Gerstell, M.F. (2003). Slope Streak Formation and Dust Deposition Rates on Mars. J. Geophys. Res., 108(E12), 5138, doi:10.1029/2003JE002123. </ref><br />
Dark slope streaks are constantly forming and fading. The darker ones are the youngest. Fading is accomplished by settling of bright dust in the Martian atmosphere. When researches looked at a small area (Lycus Sulci) on Mars with both Viking images and recent CTX images from the Mars Reconnaissance Orbiter, they found that the ones seen in Viking photos were gone, however, new streaks have taken their place. Their calculations indicated that slope streaks last about 40 years <ref>Bergonio, J., K. Rottas, and N. Schorghofer. 2013. Properties of martian slope streak populations: 225. Icarus: 194-199.</ref><br />
<br />
It is believed that during Mar's [[global dust storm|global dust storms]] many - perhaps most - streaks and other features are erased during these occosional occurences.<ref>Aharonson, O.; Schorghofer, N.; Gerstell, M.F. 2003. S lope Streak Formation and Dust Deposition Rates on Mars. J. Geophys. Res., 108(E12), 5138, doi:10.1029/2003JE002123.</ref> <ref>Schorghofer, Aharonson, O.; Gerstell, M.F.; Tatsumi, L. 2007. Three Decades of Slope Streak Activity on Mars. Icarus: 191, 132–140. doi:10.1016/j.icarus.2007.04.026.</ref><br />
<br />
<gallery class="center" widths="190px" heights="180px"><br />
File:New Streaks Formed PIA02379.jpg|New slope streaks formed near Apollinaris Mons between February 1998 and November 1999, as seen by Mars Orbital Camera (MOC).<br />
File:23677streakslabeled.jpg|Young and old dark slope streaks with origins labeled.<br />
</gallery><br />
<br />
==What causes dark slope streaks?==<br />
Although many ideas have been put forward to explain slope streaks, the general opinion today is that they are simply avalanches of darker colored dust.<ref>Treiman, A.H.; Louge, M.Y. (2004). Martian Slope Streaks and Gullies: Origins as Dry Granular Flows. 35th Lunar and Planetary Science Conference, Abstract #1323. http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1323.pdf</ref> Nearly all of Mars is covered with a thin, bright dust. On steep slopes this layer of dust can move away and reveal a dark surface. The dark volcanic rock basalt lies under the lighter-toned dust which falls out of the atmosphere.<br />
With the long term observations from orbit, researchers have noticed that strikes by meteorites can start the process of slope formation.<ref>http://www.uahirise.org/epo/nuggets/dust-avalanche.pdf</ref> <ref>https://hirise.lpl.arizona.edu/ESP_054066_1920</ref> Moreover, even the air blast from an oncoming strike can trigger clusters of slopes to form.<ref>Kaylan J. Burleigh, Henry J. Melosh, Livio L. Tornabene, Boris Ivanov, Alfred S. McEwen, Ingrid J. Daubar. 2012. Impact air blast triggers dust avalanches on Mars Icarus: 217 (1) 194 doi:10.1016/j.icarus.2011.10.026</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:ESP 054066 1920newstreak.jpg|New dark slope streak that was triggered by an impact Location is the Arabia quadrangle<br />
</gallery><br />
<br />
==Other slope features==<br />
<br />
Several features are common on slopes on Mars. The surface of Mars is billions of years old in most <br />
places. Consequently, it has accumulated many steep slopes, especially in craters and canyons. Although streaks, gullies, and recurring slope lineae all occur on slopes, they have different origins. <br />
[[Martian gullies]] show up in certain zones. However, unlike dark slope streaks they go fairly deep into the surface and are not erased by falling dust over time. Their origin is still debated. For over a decade they were believed to be formed by recent, flowing water. <br />
<ref>Malin, M.; Edgett, K. (2000). "Evidence for recent groundwater seepage and surface runoff on Mars". Science. 288: 2330–2335.</ref><br />
<ref>Luu, K., et al. 2018. GULLY FORMATION ON THE NORTHWESTERN SLOPE OF PALIKIR CRATER, MARS 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2650.pdf</ref> <br />
<ref>Hamid, S., V. Gulick. 2018. GEOMORPHOLOGICAL ANALYSIS OF GULLIES ALONG WESTERN SLOPES OF PALIKIR CRATER. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2644.pdf</ref> <br />
<ref>Tyler Paladin, T., et al. 2018. INSIGHTS INTO THE FORMATION OF GULLIES IN ASIMOV CRATER, MARS. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2889.pdf</ref> Now, new observations suggest that gullies are being made today by chunks of dry ice moving down steep slopes in the spring. <br />
<ref>Dundas, C., S. Diniega, A. McEwen. 2015. Long-term monitoring of martian gully formation and evolution with MRO/HiRISE. Icarus: 251, 244–263</ref> <br />
<ref>Fergason, R., C. Dundas, R. Anderson. 2015. IN-DEPTH REGIONAL ASSESSMENT OF THERMOPHYSICAL PROPERTIES OF ACTIVE GULLIES ON MARS. 46th Lunar and Planetary Science Conference. 2009.pdf</ref> <br />
<ref>Dundas, C. et al. 2016. HOW WET IS RECENT MARS? INSIGHTS FROM GULLIES AND RSL. 47th Lunar and Planetary Science Conference (2016) 2327.pdf. </ref> <br />
<ref>Vincendon, M. 2015. Identification of Mars gully activity<br />
types associated with ice composition.JGR:120, 1859–1879. </ref> <br />
<ref>Raack, J.; et al. (2015). "Present-day seasonal gully activity in a south polar pit (Sisyphi Cavi) on Mars". Icarus. 251: 226–243. Bibcode:2015Icar..251..226R. doi:10.1016/j.icarus.2014.03.040. </ref> <br />
<ref>http://www.uahirise.org/ESP_044327_1375</ref> <br />
<ref>C. Pilorget, C., F. Forget. 2015. "CO2 Driven Formation of Gullies on Mars." 46th Lunar and Planetary Science Conference. 2471.pdf</ref> <br />
<ref>Pilorget, C.; Forget, F. (2016). "Formation of gullies on Mars by debris flows triggered by CO2 sublimation". Nature Geoscience. 9: 65–69. Bibcode:2016NatGe...9...65P. </ref> <br />
<br />
As the map below shows gullies and streaks are found in different areas on the planet.<br />
<gallery class="center" widths="190px" heights="180px"><br />
File:Streak Locations PIA09030.jpg|Map showing locations of gullies (brown) and streaks (pink)<br />
</gallery><br />
<br />
[[File:50858 1435gullies.jpg|600pxr|Image of gullies with main parts labeled. The main parts of a Martian gully are alcove, channel, and apron. Picture was taken by HiRISE under HiWish program.]]<br />
<br />
Like gullies and streaks, recurring slope lineae are seen on steep slopes, but they are smaller, more narrow, and straighter. Since they seem to lengthen as the temperature increases, they were believed to be involved with liquid water. <ref>McEwen, A. et al. 2011. Seasonal Flows on Warm Martian Slopes. Science, 333(6043), 740–743. doi:10.1126/science.1204816 PMID 21817049. http://www.sciencemag.org/content/333/6043/740. </ref> <br />
<ref>Mann, Adam (18 February 2014). "Strange Dark Streaks on Mars Get More and More Mysterious". Wired. Retrieved 18 February 2014. </ref> <br />
<ref>Chang, K. 2011. "Scientists Find Signs Water Is Flowing on Mars," New York Times, August 4, A13. https://www.nytimes.com/2011/08/05/science/space/05mars.html?_r=1&ref=marsplanet. </ref> <br />
<ref>HiRISE website. Seasonal Flows on Warm Martian Slopes. http://hirise.lpl.arizona.edu/sim/science-2011-aug-4.php. </ref> <br />
<ref>McEwen, A. Ojha L.; Dundas C.; Mattson, S.; Byrne S.; Wray J.; Cull S.; Murchie S. 2011. Transient Slope Lineae: Evidence for Summertime Briny Flows on Mars? 42nd Lunar and Planetary Science Conference, Abstract #2314. http://www.lpi.usra.edu/meetings/lpsc2011/pdf/2314.pdf. </ref> <br />
Nevertheless, later studies showed that very little water, if any, could be involved.<ref>Dundas, C., et al. 2017. Granular Flows at Recurring Slope Lineae on Mars Indicate a Limited Role for Liquid Water. Nature Geoscience. Nov. 20. [1].</ref> <ref>Schaefer, E., et al. 2018. A case study of recurring slope lineae (RSL) at Tivat crater: Implications for RSL origins. Icarus: In press. https://doi.org/10.1016/j.icarus.2018.07.014</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:Oblique View of Warm Season Flows in Newton Crater.jpg|Recurrent slop lineae, as seen by HiRISE<br />
</gallery><br />
<br />
==References==<br />
{{reflist}}<br />
<br />
==See also==<br />
<br />
*[[Martian gullies]]<br />
*[[What Mars Actually Looks Like! ]]<br />
<br />
==External links==<br />
<br />
*[[yt:_sUUKcZaTgA|Martian Ice - Jim Secosky - 16th Annual International Mars Society Convention]]</div>Akademyhttp://marspedia.org/index.php?title=Dark_slope_streaks&diff=126250Dark slope streaks2018-09-23T17:22:18Z<p>Akademy: Adjust ref positions</p>
<hr />
<div>[[File:Fan-shaped Streaks ESP 012410 1835cropped.jpg|300px|right|Dark slope streaks, as seen by HiRISE]]<br />
Dark slope streaks are found on Mars on dust-covered slopes often near the equator, they are believed to be avalanches involving darker martian dust.<br />
<br />
==Appearance==<br />
<br />
Dark slope streaks are found on dust-covered slopes, particular near the equator.<ref name="Chuang10">Chuang, F.C.; Beyer, R.A.; Bridges, N.T. (2010). Modification of Martian Slope Streaks by Eolian Processes. ''Icarus,'' '''205''' 154–164.</ref> <br />
<br />
The streaks start out only about 10% darker than their surrounds <ref>Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref> (This is confused because many images of the streaks have been post-processed to bring out more detail and appear much darker). Over time these streaks tend to get lighter as the brighter Martian dust settles from the atmosphere. The darker ones are the newest.<br />
<br />
Typically, streaks begin at a small point high on a steep slope, such as a crater wall.<ref name="Schorghofer02">Schorghofer, N.; Aharonson, O.; Khatiwala, S. 2002. Slope Streaks on Mars: Correlations with Surface Properties and the Potential Role of Water. ''Geophys. Res. Lett.,'' '''29'''(23), 2126.</ref> And then they greatly widen and sometimes divide into finger-like extensions (digitation). Obstacles, such as boulders, may cause an individual streak to split into two separate streaks or eventually form a braided (anastomosing) pattern.<ref>Chuang, F.C. et al. 2007. HiRISE Observations of Slope Streaks on Mars. Geophys. Res. Lett., 34 L20204.</ref> Many have a fan shape. <ref>Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<br />
Streaks may be hundreds of meters long with a width of 20 to 200 meters. Indeed, some can be over 2 kilometers long. <br />
<ref>Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<ref>Chuang, F.C.; Beyer, R.A.; Bridges, N.T. 2010. Modification of Martian Slope Streaks by Eolian Processes. Icarus, 205 154–164.</ref><br />
<ref>Baratoux, D. et al. 2006. The Role of the Wind-Transported Dust in Slope Streaks Activity: Evidence from the HRSC Data. Icarus, 183 30–45.</ref><br />
<br />
<gallery class="center" widths="190px" heights="180px"><br />
File:PIA22240slopstreaks.jpg | Close view of dark slope streaks<br />
File:55107 1930streaksclose.jpg|Streak being affected by boulders. Arrows indicate boulders and resulting effect on streak.<br />
File:55480 2060streaksobstacles.jpg|Close view of streak showing boulders causing streak to divide<br />
</gallery><br />
<br />
==How long do they last?==<br />
Thanks to the many excellent cameras that we have placed in orbit over many decades, we have a history of how the Martian surface changes. Dark slope streaks are some of the most changing parts of Mars. They were discovered in Viking Orbiter pictures from the 1970,<ref name="Morris82">Morris, E.C. (1982). Aureole Deposits of the Martian Volcano Olympus Mons. ''J. Geophys. Res.,'' '''87'''(B2), 1164–1178.</ref> <ref name="Ferguson84">Ferguson,H.M.; Lucchitta, B.K. (1984). Dark Streaks on Talus Slopes, Mars in ''Reports of the Planetary Geology Program 1983, NASA Tech. Memo., TM-86246,'' pp. 188–190. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840015363_1984015363.pdf.</ref> When images from Mars Global Surveyor (MGS) and Mars Reconnaissance Orbiter (MRO) spacecraft are examined, the life history of streaks can be precisely determined.<ref>Sullivan, R. et al. (2001). Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633. </ref> <ref name="Chuang07">Chuang, F.C. et al. 2007. HiRISE Observations of Slope Streaks on Mars. 'Geophys. Res. Lett. 34 L20204.</ref> <ref>Dundas, C. 2018. HIRISE OBSERVATIONS OF NEW MARTIAN SLOPE STREAKS. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2026.pdf</ref> <ref>Malin, M.C.; Edgett, K.S. (2001). Mars Global Surveyor Mars Orbiter Camera: Interplanetary cruise through primary mission. J. Geophys. Res., 106(E10), 23,429–23,570.</ref> <ref>Edgett, K.S.; Malin, M.C.; Sullivan, R.J.; Thomas, P.; Veverka, J. (2000). Dynamic Mars: New Dark Slope Streaks Observed on Annual and Decadal Time Scales. 31st Lunar and Planetary Science Conference, Abstract #1058. http://www.lpi.usra.edu/meetings/lpsc2000/pdf/1058.pdf.</ref><br />
<br />
[[File:New Streaks Formed PIA02379.jpg|right|thumb|320px|New slope streaks formed near Apollinaris Mons between February 1998 and November 1999, as seen by Mars Orbital Camera (MOC).]]<br />
<br />
One analysis concluded that 70 streaks per day may form on the planet. The research team compared overlapping images from Mars Global Surveyor Mars Orbiter Camera that were spaced days to years apart. <ref>Aharonson, O.; Schorghofer, N.; Gerstell, M.F. (2003). Slope Streak Formation and Dust Deposition Rates on Mars. J. Geophys. Res., 108(E12), 5138, doi:10.1029/2003JE002123. </ref><br />
Dark slope streaks are constantly forming and fading. The darker ones are the youngest. Fading is accomplished by settling of bright dust in the Martian atmosphere. When researches looked at a small area (Lycus Sulci) on Mars with both Viking images and recent CTX images from the Mars Reconnaissance Orbiter, they found that the ones seen in Viking photos were gone, however, new streaks have taken their place. Their calculations indicated that slope streaks last about 40 years <ref>Bergonio, J., K. Rottas, and N. Schorghofer. 2013. Properties of martian slope streak populations: 225. Icarus: 194-199.</ref> From time to time the entire globe of Mars is enveloped in a dust storm. Many, perhaps most streaks and other features are erased during those periods.<ref>Aharonson, O.; Schorghofer, N.; Gerstell, M.F. 2003. S lope Streak Formation and Dust Deposition Rates on Mars. J. Geophys. Res., 108(E12), 5138, doi:10.1029/2003JE002123.</ref> <ref>Schorghofer, Aharonson, O.; Gerstell, M.F.; Tatsumi, L. 2007. Three Decades of Slope Streak Activity on Mars. Icarus: 191, 132–140. doi:10.1016/j.icarus.2007.04.026.</ref><br />
<br />
<gallery class="center" widths="190px" heights="180px"><br />
<br />
File:23677streakslabeled.jpg|Young and old dark slope streaks with origins labeled.<br />
<br />
File: PIA03170 fig1duststroms.jpg|Mars without a dust storm on June 2001 (on left) and with a global dust storm on July 2001 (on right), as seen by Mars Global Surveyor<br />
</gallery><br />
<br />
==What causes dark slope streaks?==<br />
Although many ideas have been put forward to explain slope streaks, the general opinion today is that they are simply avalanches of darker colored dust.<ref>Treiman, A.H.; Louge, M.Y. (2004). Martian Slope Streaks and Gullies: Origins as Dry Granular Flows. 35th Lunar and Planetary Science Conference, Abstract #1323. http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1323.pdf</ref> Nearly all of Mars is covered with a thin, bright dust. On steep slopes this layer of dust can move away and reveal a dark surface. The dark volcanic rock basalt lies under the lighter-toned dust which falls out of the atmosphere.<br />
With the long term observations from orbit, researchers have noticed that strikes by meteorites can start the process of slope formation.<ref>http://www.uahirise.org/epo/nuggets/dust-avalanche.pdf</ref> <ref>https://hirise.lpl.arizona.edu/ESP_054066_1920</ref> Moreover, even the air blast from an oncoming strike can trigger clusters of slopes to form.<ref>Kaylan J. Burleigh, Henry J. Melosh, Livio L. Tornabene, Boris Ivanov, Alfred S. McEwen, Ingrid J. Daubar. 2012. Impact air blast triggers dust avalanches on Mars Icarus: 217 (1) 194 doi:10.1016/j.icarus.2011.10.026</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:ESP 054066 1920newstreak.jpg|New dark slope streak that was triggered by an impact Location is the Arabia quadrangle<br />
</gallery><br />
<br />
==Other slope features==<br />
<br />
Several features are common on slopes on Mars. The surface of Mars is billions of years old in most <br />
places. Consequently, it has accumulated many steep slopes, especially in craters and canyons. Although streaks, gullies, and recurring slope lineae all occur on slopes, they have different origins. <br />
[[Martian gullies]] show up in certain zones. However, unlike dark slope streaks they go fairly deep into the surface and are not erased by falling dust over time. Their origin is still debated. For over a decade they were believed to be formed by recent, flowing water. <br />
<ref>Malin, M.; Edgett, K. (2000). "Evidence for recent groundwater seepage and surface runoff on Mars". Science. 288: 2330–2335.</ref><br />
<ref>Luu, K., et al. 2018. GULLY FORMATION ON THE NORTHWESTERN SLOPE OF PALIKIR CRATER, MARS 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2650.pdf</ref> <br />
<ref>Hamid, S., V. Gulick. 2018. GEOMORPHOLOGICAL ANALYSIS OF GULLIES ALONG WESTERN SLOPES OF PALIKIR CRATER. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2644.pdf</ref> <br />
<ref>Tyler Paladin, T., et al. 2018. INSIGHTS INTO THE FORMATION OF GULLIES IN ASIMOV CRATER, MARS. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2889.pdf</ref> Now, new observations suggest that gullies are being made today by chunks of dry ice moving down steep slopes in the spring. <br />
<ref>Dundas, C., S. Diniega, A. McEwen. 2015. Long-term monitoring of martian gully formation and evolution with MRO/HiRISE. Icarus: 251, 244–263</ref> <br />
<ref>Fergason, R., C. Dundas, R. Anderson. 2015. IN-DEPTH REGIONAL ASSESSMENT OF THERMOPHYSICAL PROPERTIES OF ACTIVE GULLIES ON MARS. 46th Lunar and Planetary Science Conference. 2009.pdf</ref> <br />
<ref>Dundas, C. et al. 2016. HOW WET IS RECENT MARS? INSIGHTS FROM GULLIES AND RSL. 47th Lunar and Planetary Science Conference (2016) 2327.pdf. </ref> <br />
<ref>Vincendon, M. 2015. Identification of Mars gully activity<br />
types associated with ice composition.JGR:120, 1859–1879. </ref> <br />
<ref>Raack, J.; et al. (2015). "Present-day seasonal gully activity in a south polar pit (Sisyphi Cavi) on Mars". Icarus. 251: 226–243. Bibcode:2015Icar..251..226R. doi:10.1016/j.icarus.2014.03.040. </ref> <br />
<ref>http://www.uahirise.org/ESP_044327_1375</ref> <br />
<ref>C. Pilorget, C., F. Forget. 2015. "CO2 Driven Formation of Gullies on Mars." 46th Lunar and Planetary Science Conference. 2471.pdf</ref> <br />
<ref>Pilorget, C.; Forget, F. (2016). "Formation of gullies on Mars by debris flows triggered by CO2 sublimation". Nature Geoscience. 9: 65–69. Bibcode:2016NatGe...9...65P. </ref> <br />
<br />
As the map below shows gullies and streaks are found in different areas on the planet.<br />
<gallery class="center" widths="190px" heights="180px"><br />
File:Streak Locations PIA09030.jpg|Map showing locations of gullies (brown) and streaks (pink)<br />
</gallery><br />
<br />
[[File:50858 1435gullies.jpg|600pxr|Image of gullies with main parts labeled. The main parts of a Martian gully are alcove, channel, and apron. Picture was taken by HiRISE under HiWish program.]]<br />
<br />
Like gullies and streaks, recurring slope lineae are seen on steep slopes, but they are smaller, more narrow, and straighter. Since they seem to lengthen as the temperature increases, they were believed to be involved with liquid water. <ref>McEwen, A. et al. 2011. Seasonal Flows on Warm Martian Slopes. Science, 333(6043), 740–743. doi:10.1126/science.1204816 PMID 21817049. http://www.sciencemag.org/content/333/6043/740. </ref> <br />
<ref>Mann, Adam (18 February 2014). "Strange Dark Streaks on Mars Get More and More Mysterious". Wired. Retrieved 18 February 2014. </ref> <br />
<ref>Chang, K. 2011. "Scientists Find Signs Water Is Flowing on Mars," New York Times, August 4, A13. https://www.nytimes.com/2011/08/05/science/space/05mars.html?_r=1&ref=marsplanet. </ref> <br />
<ref>HiRISE website. Seasonal Flows on Warm Martian Slopes. http://hirise.lpl.arizona.edu/sim/science-2011-aug-4.php. </ref> <br />
<ref>McEwen, A. Ojha L.; Dundas C.; Mattson, S.; Byrne S.; Wray J.; Cull S.; Murchie S. 2011. Transient Slope Lineae: Evidence for Summertime Briny Flows on Mars? 42nd Lunar and Planetary Science Conference, Abstract #2314. http://www.lpi.usra.edu/meetings/lpsc2011/pdf/2314.pdf. </ref> <br />
Nevertheless, later studies showed that very little water, if any, could be involved.<ref>Dundas, C., et al. 2017. Granular Flows at Recurring Slope Lineae on Mars Indicate a Limited Role for Liquid Water. Nature Geoscience. Nov. 20. [1].</ref> <ref>Schaefer, E., et al. 2018. A case study of recurring slope lineae (RSL) at Tivat crater: Implications for RSL origins. Icarus: In press. https://doi.org/10.1016/j.icarus.2018.07.014</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:Oblique View of Warm Season Flows in Newton Crater.jpg|Recurrent slop lineae, as seen by HiRISE<br />
</gallery><br />
<br />
==References==<br />
{{reflist}}<br />
<br />
==See also==<br />
<br />
*[[Martian gullies]]<br />
*[[What Mars Actually Looks Like! ]]<br />
<br />
==External links==<br />
<br />
*[[yt:_sUUKcZaTgA|Martian Ice - Jim Secosky - 16th Annual International Mars Society Convention]]</div>Akademyhttp://marspedia.org/index.php?title=Dark_slope_streaks&diff=126249Dark slope streaks2018-09-23T17:19:35Z<p>Akademy: More clear information on appearance.</p>
<hr />
<div>[[File:Fan-shaped Streaks ESP 012410 1835cropped.jpg|300px|right|Dark slope streaks, as seen by HiRISE]]<br />
Dark slope streaks are found on Mars on dust-covered slopes often near the equator, they are believed to be avalanches involving darker martian dust.<br />
<br />
==Appearance==<br />
<br />
Dark slope streaks are found on dust-covered slopes, particular near the equator.<ref name="Chuang10">Chuang, F.C.; Beyer, R.A.; Bridges, N.T. (2010). Modification of Martian Slope Streaks by Eolian Processes. ''Icarus,'' '''205''' 154–164.</ref> <br />
<br />
The streaks start out only about 10% darker than their surrounds <ref>Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref> (This is confused because many images of the streaks have been post-processed to bring out more detail and appear much darker). Over time these streaks tend to get lighter as the brighter Martian dust settles from the atmosphere. The darker ones are the newest.<br />
<br />
Typically, streaks begin at a small point high on a steep slope, such as a crater wall.<ref name="Schorghofer02">Schorghofer, N.; Aharonson, O.; Khatiwala, S. 2002. Slope Streaks on Mars: Correlations with Surface Properties and the Potential Role of Water. ''Geophys. Res. Lett.,'' '''29'''(23), 2126.</ref> And then they greatly widen and sometimes divide into finger-like extensions (digitation). Obstacles, such as boulders, may cause an individual streak to split into two separate streaks or eventually form a braided (anastomosing) pattern.<ref>Chuang, F.C. et al. 2007. HiRISE Observations of Slope Streaks on Mars. Geophys. Res. Lett., 34 L20204.</ref> Many have a fan shape. <ref>Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<br />
Streaks may be hundreds of meters long with a width of 20 to 200 meters. Indeed, some can be over 2 kilometers long. <br />
<ref>Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<ref>Chuang, F.C.; Beyer, R.A.; Bridges, N.T. 2010. Modification of Martian Slope Streaks by Eolian Processes. Icarus, 205 154–164.</ref><br />
<ref>Baratoux, D. et al. 2006. The Role of the Wind-Transported Dust in Slope Streaks Activity: Evidence from the HRSC Data. Icarus, 183 30–45.</ref><br />
<br />
<gallery class="center" widths="190px" heights="180px"><br />
File:PIA22240slopstreaks.jpg | Close view of dark slope streaks<br />
File:55107 1930streaksclose.jpg|Streak being affected by boulders. Arrows indicate boulders and resulting effect on streak.<br />
File:55480 2060streaksobstacles.jpg|Close view of streak showing boulders causing streak to divide<br />
</gallery><br />
<br />
==How long do they last?==<br />
Thanks to the many excellent cameras that we have placed in orbit over many decades, we have a history of how the Martian surface changes. Dark slope streaks are some of the most changing parts of Mars. They were discovered in Viking Orbiter pictures from the 1970,<ref name="Morris82">Morris, E.C. (1982). Aureole Deposits of the Martian Volcano Olympus Mons. ''J. Geophys. Res.,'' '''87'''(B2), 1164–1178.</ref> <ref name="Ferguson84">Ferguson,H.M.; Lucchitta, B.K. (1984). Dark Streaks on Talus Slopes, Mars in ''Reports of the Planetary Geology Program 1983, NASA Tech. Memo., TM-86246,'' pp. 188–190. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840015363_1984015363.pdf.</ref> When images from Mars Global Surveyor (MGS) and Mars Reconnaissance Orbiter (MRO) spacecraft are examined, the life history of streaks can be precisely determined.<ref>Sullivan, R. et al. (2001). Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633. </ref> <ref name="Chuang07">Chuang, F.C. et al. 2007. HiRISE Observations of Slope Streaks on Mars. 'Geophys. Res. Lett. 34 L20204.</ref> <ref>Dundas, C. 2018. HIRISE OBSERVATIONS OF NEW MARTIAN SLOPE STREAKS. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2026.pdf</ref> <ref>Malin, M.C.; Edgett, K.S. (2001). Mars Global Surveyor Mars Orbiter Camera: Interplanetary cruise through primary mission. J. Geophys. Res., 106(E10), 23,429–23,570.</ref> <ref>Edgett, K.S.; Malin, M.C.; Sullivan, R.J.; Thomas, P.; Veverka, J. (2000). Dynamic Mars: New Dark Slope Streaks Observed on Annual and Decadal Time Scales. 31st Lunar and Planetary Science Conference, Abstract #1058. http://www.lpi.usra.edu/meetings/lpsc2000/pdf/1058.pdf.</ref><br />
<br />
[[File:New Streaks Formed PIA02379.jpg|right|thumb|320px|New slope streaks formed near Apollinaris Mons between February 1998 and November 1999, as seen by Mars Orbital Camera (MOC).]]<br />
<br />
One analysis concluded that 70 streaks per day may form on the planet. The research team compared overlapping images from Mars Global Surveyor Mars Orbiter Camera that were spaced days to years apart. <ref>Aharonson, O.; Schorghofer, N.; Gerstell, M.F. (2003). Slope Streak Formation and Dust Deposition Rates on Mars. J. Geophys. Res., 108(E12), 5138, doi:10.1029/2003JE002123. </ref><br />
Dark slope streaks are constantly forming and fading. The darker ones are the youngest. Fading is accomplished by settling of bright dust in the Martian atmosphere. When researches looked at a small area (Lycus Sulci) on Mars with both Viking images and recent CTX images from the Mars Reconnaissance Orbiter, they found that the ones seen in Viking photos were gone, however, new streaks have taken their place. Their calculations indicated that slope streaks last about 40 years <ref>Bergonio, J., K. Rottas, and N. Schorghofer. 2013. Properties of martian slope streak populations: 225. Icarus: 194-199.</ref> From time to time the entire globe of Mars is enveloped in a dust storm. Many, perhaps most streaks and other features are erased during those periods.<ref>Aharonson, O.; Schorghofer, N.; Gerstell, M.F. 2003. S lope Streak Formation and Dust Deposition Rates on Mars. J. Geophys. Res., 108(E12), 5138, doi:10.1029/2003JE002123.</ref> <ref>Schorghofer, Aharonson, O.; Gerstell, M.F.; Tatsumi, L. 2007. Three Decades of Slope Streak Activity on Mars. Icarus: 191, 132–140. doi:10.1016/j.icarus.2007.04.026.</ref><br />
<br />
<gallery class="center" widths="190px" heights="180px"><br />
<br />
File:23677streakslabeled.jpg|Young and old dark slope streaks with origins labeled.<br />
<br />
File: PIA03170 fig1duststroms.jpg|Mars without a dust storm on June 2001 (on left) and with a global dust storm on July 2001 (on right), as seen by Mars Global Surveyor<br />
</gallery><br />
<br />
==What causes dark slope streaks?==<br />
Although many ideas have been put forward to explain slope streaks, the general opinion today is that they are simply avalanches of darker colored dust.<ref>Treiman, A.H.; Louge, M.Y. (2004). Martian Slope Streaks and Gullies: Origins as Dry Granular Flows. 35th Lunar and Planetary Science Conference, Abstract #1323. http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1323.pdf</ref> Nearly all of Mars is covered with a thin, bright dust. On steep slopes this layer of dust can move away and reveal a dark surface. The dark volcanic rock basalt lies under the lighter-toned dust which falls out of the atmosphere.<br />
With the long term observations from orbit, researchers have noticed that strikes by meteorites can start the process of slope formation.<ref>http://www.uahirise.org/epo/nuggets/dust-avalanche.pdf</ref> <ref>https://hirise.lpl.arizona.edu/ESP_054066_1920</ref> Moreover, even the air blast from an oncoming strike can trigger clusters of slopes to form.<ref>Kaylan J. Burleigh, Henry J. Melosh, Livio L. Tornabene, Boris Ivanov, Alfred S. McEwen, Ingrid J. Daubar. 2012. Impact air blast triggers dust avalanches on Mars Icarus: 217 (1) 194 doi:10.1016/j.icarus.2011.10.026</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:ESP 054066 1920newstreak.jpg|New dark slope streak that was triggered by an impact Location is the Arabia quadrangle<br />
</gallery><br />
<br />
==Other slope features==<br />
<br />
Several features are common on slopes on Mars. The surface of Mars is billions of years old in most <br />
places. Consequently, it has accumulated many steep slopes, especially in craters and canyons. Although streaks, gullies, and recurring slope lineae all occur on slopes, they have different origins. <br />
[[Martian gullies]] show up in certain zones. However, unlike dark slope streaks they go fairly deep into the surface and are not erased by falling dust over time. Their origin is still debated. For over a decade they were believed to be formed by recent, flowing water. <br />
<br />
<ref>Malin, M.; Edgett, K. (2000). "Evidence for recent groundwater seepage and surface runoff on Mars". Science. 288: 2330–2335.</ref><br />
<ref>Luu, K., et al. 2018. GULLY FORMATION ON THE NORTHWESTERN SLOPE OF PALIKIR CRATER, MARS 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2650.pdf</ref> <br />
<ref>Hamid, S., V. Gulick. 2018. GEOMORPHOLOGICAL ANALYSIS OF GULLIES ALONG WESTERN SLOPES OF PALIKIR CRATER. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2644.pdf</ref> <br />
<ref>Tyler Paladin, T., et al. 2018. INSIGHTS INTO THE FORMATION OF GULLIES IN ASIMOV CRATER, MARS. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2889.pdf</ref> Now, new observations suggest that gullies are being made today by chunks of dry ice moving down steep slopes in the spring. <br />
<ref>Dundas, C., S. Diniega, A. McEwen. 2015. Long-term monitoring of martian gully formation and evolution with MRO/HiRISE. Icarus: 251, 244–263</ref> <br />
<ref>Fergason, R., C. Dundas, R. Anderson. 2015. IN-DEPTH REGIONAL ASSESSMENT OF THERMOPHYSICAL PROPERTIES OF ACTIVE GULLIES ON MARS. 46th Lunar and Planetary Science Conference. 2009.pdf</ref> <br />
<ref>Dundas, C. et al. 2016. HOW WET IS RECENT MARS? INSIGHTS FROM GULLIES AND RSL. 47th Lunar and Planetary Science Conference (2016) 2327.pdf. </ref> <br />
<ref>Vincendon, M. 2015. Identification of Mars gully activity<br />
types associated with ice composition.JGR:120, 1859–1879. </ref> <br />
<ref>Raack, J.; et al. (2015). "Present-day seasonal gully activity in a south polar pit (Sisyphi Cavi) on Mars". Icarus. 251: 226–243. Bibcode:2015Icar..251..226R. doi:10.1016/j.icarus.2014.03.040. </ref> <br />
<ref>http://www.uahirise.org/ESP_044327_1375</ref> <br />
<ref>C. Pilorget, C., F. Forget. 2015. "CO2 Driven Formation of Gullies on Mars." 46th Lunar and Planetary Science Conference. 2471.pdf</ref> <br />
<ref>Pilorget, C.; Forget, F. (2016). "Formation of gullies on Mars by debris flows triggered by CO2 sublimation". Nature Geoscience. 9: 65–69. Bibcode:2016NatGe...9...65P. </ref> <br />
As the map below shows gullies and streaks are found in different areas on the planet.<br />
<gallery class="center" widths="190px" heights="180px"><br />
File:Streak Locations PIA09030.jpg|Map showing locations of gullies (brown) and streaks (pink)<br />
</gallery><br />
<br />
[[File:50858 1435gullies.jpg|600pxr|Image of gullies with main parts labeled. The main parts of a Martian gully are alcove, channel, and apron. Picture was taken by HiRISE under HiWish program.]]<br />
<br />
Like gullies and streaks, recurring slope lineae are seen on steep slopes, but they are smaller, more narrow, and straighter. Since they seem to lengthen as the temperature increases, they were believed to be involved with liquid water. <ref>McEwen, A. et al. 2011. Seasonal Flows on Warm Martian Slopes. Science, 333(6043), 740–743. doi:10.1126/science.1204816 PMID 21817049. http://www.sciencemag.org/content/333/6043/740. </ref> <br />
<ref>Mann, Adam (18 February 2014). "Strange Dark Streaks on Mars Get More and More Mysterious". Wired. Retrieved 18 February 2014. </ref> <br />
<ref>Chang, K. 2011. "Scientists Find Signs Water Is Flowing on Mars," New York Times, August 4, A13. https://www.nytimes.com/2011/08/05/science/space/05mars.html?_r=1&ref=marsplanet. </ref> <br />
<ref>HiRISE website. Seasonal Flows on Warm Martian Slopes. http://hirise.lpl.arizona.edu/sim/science-2011-aug-4.php. </ref> <br />
<ref>McEwen, A. Ojha L.; Dundas C.; Mattson, S.; Byrne S.; Wray J.; Cull S.; Murchie S. 2011. Transient Slope Lineae: Evidence for Summertime Briny Flows on Mars? 42nd Lunar and Planetary Science Conference, Abstract #2314. http://www.lpi.usra.edu/meetings/lpsc2011/pdf/2314.pdf. </ref> <br />
Nevertheless, later studies showed that very little water, if any, could be involved.<ref>Dundas, C., et al. 2017. Granular Flows at Recurring Slope Lineae on Mars Indicate a Limited Role for Liquid Water. Nature Geoscience. Nov. 20. [1].</ref> <ref>Schaefer, E., et al. 2018. A case study of recurring slope lineae (RSL) at Tivat crater: Implications for RSL origins. Icarus: In press. https://doi.org/10.1016/j.icarus.2018.07.014</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:Oblique View of Warm Season Flows in Newton Crater.jpg|Recurrent slop lineae, as seen by HiRISE<br />
</gallery><br />
<br />
==References==<br />
{{reflist}}<br />
<br />
==See also==<br />
<br />
*[[Martian gullies]]<br />
*[[What Mars Actually Looks Like! ]]<br />
<br />
==External links==<br />
<br />
*[[yt:_sUUKcZaTgA|Martian Ice - Jim Secosky - 16th Annual International Mars Society Convention]]</div>Akademyhttp://marspedia.org/index.php?title=Dark_slope_streaks&diff=126248Dark slope streaks2018-09-23T17:03:45Z<p>Akademy: Reordering</p>
<hr />
<div>[[File:Fan-shaped Streaks ESP 012410 1835cropped.jpg|300px|right|Dark slope streaks, as seen by HiRISE]]<br />
Dark slope streaks are found on Mars on dust-covered slopes often near the equator, they are believed to be avalanches involving darker martian dust.<br />
<br />
==Appearance==<br />
<br />
Perhaps some of the prettiest landscapes on Mars, dark slope streaks are found on dust-covered slopes, particular near the equator.<ref name=Chuang10>Chuang, F.C.; Beyer, R.A.; Bridges, N.T. (2010). Modification of Martian Slope Streaks by Eolian Processes. ''Icarus,'' '''205''' 154–164.</ref> However, much of their beauty comes from the post-processing of the images. They are adjusted to bring out more detail by setting the darkest part of the image to black. Streaks are actually only about 10% darker than their surroundings. <ref>Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<br />
Typically, streaks begin at a small point high on a steep slope, such as a crater wall.<ref name= Schorghofer02>Schorghofer, N.; Aharonson, O.; Khatiwala, S. 2002. Slope Streaks on Mars: Correlations with Surface Properties and the Potential Role of Water. ''Geophys. Res. Lett.,'' '''29'''(23), 2126.</ref> And then they greatly widen and sometimes divide into finger-like extensions (digitation). Obstacles, such as boulders, may cause an individual streak to split into two separate streaks or eventually form a braided (anastomosing) pattern.<ref> Chuang, F.C. et al. 2007. HiRISE Observations of Slope Streaks on Mars. Geophys. Res. Lett., 34 L20204.</ref> Many have a fan shape. <ref> Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<br />
Streaks may be hundreds of meters long with a width of 20 to 200 meters. Indeed, some can be over 2 kilometers long. <br />
<ref> Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<ref> Chuang, F.C.; Beyer, R.A.; Bridges, N.T. 2010. Modification of Martian Slope Streaks by Eolian Processes. Icarus, 205 154–164.</ref><br />
<ref> Baratoux, D. et al. 2006. The Role of the Wind-Transported Dust in Slope Streaks Activity: Evidence from the HRSC Data. Icarus, 183 30–45.</ref><br />
<br />
<gallery class="center" widths="190px" heights="180px"><br />
File:PIA22240slopstreaks.jpg | Close view of dark slope streaks<br />
File:55107 1930streaksclose.jpg|Streak being affected by boulders. Arrows indicate boulders and resulting effect on streak.<br />
File:55480 2060streaksobstacles.jpg|Close view of streak showing boulders causing streak to divide<br />
</gallery><br />
<br />
== How long do they last? ==<br />
Thanks to the many excellent cameras that we have placed in orbit over many decades, we have a history of how the Martian surface changes. Dark slope streaks are some of the most changing parts of Mars. They were discovered in Viking Orbiter pictures from the 1970,<ref name=Morris82>Morris, E.C. (1982). Aureole Deposits of the Martian Volcano Olympus Mons. ''J. Geophys. Res.,'' '''87'''(B2), 1164–1178.</ref> <ref name=Ferguson84>Ferguson,H.M.; Lucchitta, B.K. (1984). Dark Streaks on Talus Slopes, Mars in ''Reports of the Planetary Geology Program 1983, NASA Tech. Memo., TM-86246,'' pp. 188–190. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840015363_1984015363.pdf.</ref> When images from Mars Global Surveyor (MGS) and Mars Reconnaissance Orbiter (MRO) spacecraft are examined, the life history of streaks can be precisely determined.<ref>Sullivan, R. et al. (2001). Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633. </ref> <ref name=Chuang07>Chuang, F.C. et al. 2007. HiRISE Observations of Slope Streaks on Mars. 'Geophys. Res. Lett. 34 L20204.</ref> <ref>Dundas, C. 2018. HIRISE OBSERVATIONS OF NEW MARTIAN SLOPE STREAKS. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2026.pdf</ref> <ref> Malin, M.C.; Edgett, K.S. (2001). Mars Global Surveyor Mars Orbiter Camera: Interplanetary cruise through primary mission. J. Geophys. Res., 106(E10), 23,429–23,570.</ref> <br />
<ref> Edgett, K.S.; Malin, M.C.; Sullivan, R.J.; Thomas, P.; Veverka, J. (2000). Dynamic Mars: New Dark Slope Streaks Observed on Annual and Decadal Time Scales. 31st Lunar and Planetary Science Conference, Abstract #1058. http://www.lpi.usra.edu/meetings/lpsc2000/pdf/1058.pdf.</ref><br />
<br />
[[File:New Streaks Formed PIA02379.jpg|right|thumb|320px|New slope streaks formed near Apollinaris Mons between February 1998 and November 1999, as seen by Mars Orbital Camera (MOC).]]<br />
<br />
One analysis concluded that 70 streaks per day may form on the planet. The research team compared overlapping images from Mars Global Surveyor Mars Orbiter Camera that were spaced days to years apart. <ref> Aharonson, O.; Schorghofer, N.; Gerstell, M.F. (2003). Slope Streak Formation and Dust Deposition Rates on Mars. J. Geophys. Res., 108(E12), 5138, doi:10.1029/2003JE002123. </ref><br />
Dark slope streaks are constantly forming and fading. The darker ones are the youngest. Fading is accomplished by settling of bright dust in the Martian atmosphere. When researches looked at a small area (Lycus Sulci) on Mars with both Viking images and recent CTX images from the Mars Reconnaissance Orbiter, they found that the ones seen in Viking photos were gone, however, new streaks have taken their place. Their calculations indicated that slope streaks last about 40 years <ref> Bergonio, J., K. Rottas, and N. Schorghofer. 2013. Properties of martian slope streak populations: 225. Icarus: 194-199.</ref> From time to time the entire globe of Mars is enveloped in a dust storm. Many, perhaps most streaks and other features are erased during those periods.<ref> Aharonson, O.; Schorghofer, N.; Gerstell, M.F. 2003. S lope Streak Formation and Dust Deposition Rates on Mars. J. Geophys. Res., 108(E12), 5138, doi:10.1029/2003JE002123.</ref> <ref> Schorghofer, Aharonson, O.; Gerstell, M.F.; Tatsumi, L. 2007. Three Decades of Slope Streak Activity on Mars. Icarus: 191, 132–140. doi:10.1016/j.icarus.2007.04.026.</ref><br />
<br />
<gallery class="center" widths="190px" heights="180px"><br />
<br />
File:23677streakslabeled.jpg|Young and old dark slope streaks with origins labeled.<br />
<br />
File: PIA03170 fig1duststroms.jpg|Mars without a dust storm on June 2001 (on left) and with a global dust storm on July 2001 (on right), as seen by Mars Global Surveyor<br />
</gallery><br />
<br />
==What causes dark slope streaks?==<br />
Although many ideas have been put forward to explain slope streaks, the general opinion today is that they are simply avalanches of darker colored dust.<ref> Treiman, A.H.; Louge, M.Y. (2004). Martian Slope Streaks and Gullies: Origins as Dry Granular Flows. 35th Lunar and Planetary Science Conference, Abstract #1323. http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1323.pdf</ref> Nearly all of Mars is covered with a thin, bright dust. On steep slopes this layer of dust can move away and reveal a dark surface. The dark volcanic rock basalt lies under the lighter-toned dust which falls out of the atmosphere.<br />
With the long term observations from orbit, researchers have noticed that strikes by meteorites can start the process of slope formation.<ref> http://www.uahirise.org/epo/nuggets/dust-avalanche.pdf</ref> <ref>https://hirise.lpl.arizona.edu/ESP_054066_1920</ref> Moreover, even the air blast from an oncoming strike can trigger clusters of slopes to form.<ref>Kaylan J. Burleigh, Henry J. Melosh, Livio L. Tornabene, Boris Ivanov, Alfred S. McEwen, Ingrid J. Daubar. 2012. Impact air blast triggers dust avalanches on Mars Icarus: 217 (1) 194 doi:10.1016/j.icarus.2011.10.026</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:ESP 054066 1920newstreak.jpg|New dark slope streak that was triggered by an impact Location is the Arabia quadrangle<br />
</gallery><br />
<br />
==Other slope features==<br />
<br />
Several features are common on slopes on Mars. The surface of Mars is billions of years old in most <br />
places. Consequently, it has accumulated many steep slopes, especially in craters and canyons. Although streaks, gullies, and recurring slope lineae all occur on slopes, they have different origins. <br />
[[Martian gullies]] show up in certain zones. However, unlike dark slope streaks they go fairly deep into the surface and are not erased by falling dust over time. Their origin is still debated. For over a decade they were believed to be formed by recent, flowing water. <br />
<br />
<ref>Malin, M.; Edgett, K. (2000). "Evidence for recent groundwater seepage and surface runoff on Mars". Science. 288: 2330–2335.</ref><br />
<ref> Luu, K., et al. 2018. GULLY FORMATION ON THE NORTHWESTERN SLOPE OF PALIKIR CRATER, MARS 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2650.pdf</ref> <br />
<ref> Hamid, S., V. Gulick. 2018. GEOMORPHOLOGICAL ANALYSIS OF GULLIES ALONG WESTERN SLOPES OF PALIKIR CRATER. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2644.pdf</ref> <br />
<ref> Tyler Paladin, T., et al. 2018. INSIGHTS INTO THE FORMATION OF GULLIES IN ASIMOV CRATER, MARS. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2889.pdf</ref> Now, new observations suggest that gullies are being made today by chunks of dry ice moving down steep slopes in the spring. <br />
<ref> Dundas, C., S. Diniega, A. McEwen. 2015. Long-term monitoring of martian gully formation and evolution with MRO/HiRISE. Icarus: 251, 244–263</ref> <br />
<ref> Fergason, R., C. Dundas, R. Anderson. 2015. IN-DEPTH REGIONAL ASSESSMENT OF THERMOPHYSICAL PROPERTIES OF ACTIVE GULLIES ON MARS. 46th Lunar and Planetary Science Conference. 2009.pdf</ref> <br />
<ref> Dundas, C. et al. 2016. HOW WET IS RECENT MARS? INSIGHTS FROM GULLIES AND RSL. 47th Lunar and Planetary Science Conference (2016) 2327.pdf. </ref> <br />
<ref> Vincendon, M. 2015. Identification of Mars gully activity<br />
types associated with ice composition.JGR:120, 1859–1879. </ref> <br />
<ref> Raack, J.; et al. (2015). "Present-day seasonal gully activity in a south polar pit (Sisyphi Cavi) on Mars". Icarus. 251: 226–243. Bibcode:2015Icar..251..226R. doi:10.1016/j.icarus.2014.03.040. </ref> <br />
<ref> http://www.uahirise.org/ESP_044327_1375</ref> <br />
<ref> C. Pilorget, C., F. Forget. 2015. "CO2 Driven Formation of Gullies on Mars." 46th Lunar and Planetary Science Conference. 2471.pdf</ref> <br />
<ref> Pilorget, C.; Forget, F. (2016). "Formation of gullies on Mars by debris flows triggered by CO2 sublimation". Nature Geoscience. 9: 65–69. Bibcode:2016NatGe...9...65P. </ref> <br />
As the map below shows gullies and streaks are found in different areas on the planet.<br />
<gallery class="center" widths="190px" heights="180px"><br />
File:Streak Locations PIA09030.jpg|Map showing locations of gullies (brown) and streaks (pink)<br />
</gallery><br />
<br />
[[File:50858 1435gullies.jpg|600pxr|Image of gullies with main parts labeled. The main parts of a Martian gully are alcove, channel, and apron. Picture was taken by HiRISE under HiWish program.]]<br />
<br />
Like gullies and streaks, recurring slope lineae are seen on steep slopes, but they are smaller, more narrow, and straighter. Since they seem to lengthen as the temperature increases, they were believed to be involved with liquid water. <ref> McEwen, A. et al. 2011. Seasonal Flows on Warm Martian Slopes. Science, 333(6043), 740–743. doi:10.1126/science.1204816 PMID 21817049. http://www.sciencemag.org/content/333/6043/740. </ref> <br />
<ref> Mann, Adam (18 February 2014). "Strange Dark Streaks on Mars Get More and More Mysterious". Wired. Retrieved 18 February 2014. </ref> <br />
<ref> Chang, K. 2011. "Scientists Find Signs Water Is Flowing on Mars," New York Times, August 4, A13. https://www.nytimes.com/2011/08/05/science/space/05mars.html?_r=1&ref=marsplanet. </ref> <br />
<ref> HiRISE website. Seasonal Flows on Warm Martian Slopes. http://hirise.lpl.arizona.edu/sim/science-2011-aug-4.php. </ref> <br />
<ref> McEwen, A. Ojha L.; Dundas C.; Mattson, S.; Byrne S.; Wray J.; Cull S.; Murchie S. 2011. Transient Slope Lineae: Evidence for Summertime Briny Flows on Mars? 42nd Lunar and Planetary Science Conference, Abstract #2314. http://www.lpi.usra.edu/meetings/lpsc2011/pdf/2314.pdf. </ref> <br />
Nevertheless, later studies showed that very little water, if any, could be involved.<ref>Dundas, C., et al. 2017. Granular Flows at Recurring Slope Lineae on Mars Indicate a Limited Role for Liquid Water. Nature Geoscience. Nov. 20. [1].</ref> <ref>Schaefer, E., et al. 2018. A case study of recurring slope lineae (RSL) at Tivat crater: Implications for RSL origins. Icarus: In press. https://doi.org/10.1016/j.icarus.2018.07.014</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:Oblique View of Warm Season Flows in Newton Crater.jpg|Recurrent slop lineae, as seen by HiRISE<br />
</gallery><br />
<br />
== References ==<br />
{{reflist}}<br />
<br />
==See also==<br />
* [[Martian gullies]]<br />
* [[What Mars Actually Looks Like! ]] <br />
== External links ==<br />
* [[yt:_sUUKcZaTgA|Martian Ice - Jim Secosky - 16th Annual International Mars Society Convention]]</div>Akademyhttp://marspedia.org/index.php?title=Dark_slope_streaks&diff=126247Dark slope streaks2018-09-23T16:57:45Z<p>Akademy: Improve summary.</p>
<hr />
<div>[[File:Fan-shaped Streaks ESP 012410 1835cropped.jpg|300px|right|Dark slope streaks, as seen by HiRISE]]<br />
Dark slope streaks are found on Mars on dust-covered slopes often near the equator, they are believed to be avalanches involving darker martian dust.<br />
<br />
==Appearance==<br />
<br />
Perhaps, some of the prettiest landscapes on Mars, dark slope streaks are found on dust-covered slopes, particular near the equator.<ref name=Chuang10>Chuang, F.C.; Beyer, R.A.; Bridges, N.T. (2010). Modification of Martian Slope Streaks by Eolian Processes. ''Icarus,'' '''205''' 154–164.</ref> However, much of their beauty is from the way images are processed. Scientists set the darkest part of the image to black to more easily see detail, but this darkest part is unlikely to actually be black. Streaks are actually only about 10% darker than their surroundings. <ref>Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:PIA22240slopstreaks.jpg | Close view of dark slope streaks<br />
</gallery><br />
<br />
Typically, streaks begin at a small point high on a steep slope, such as a crater wall.<ref name= Schorghofer02>Schorghofer, N.; Aharonson, O.; Khatiwala, S. 2002. Slope Streaks on Mars: Correlations with Surface Properties and the Potential Role of Water. ''Geophys. Res. Lett.,'' '''29'''(23), 2126.</ref> And then they greatly widen and sometimes divide into finger-like extensions (digitation). Obstacles, such as boulders, may cause an individual streak to split into two separate streaks or eventually form a braided (anastomosing) pattern.<ref> Chuang, F.C. et al. 2007. HiRISE Observations of Slope Streaks on Mars. Geophys. Res. Lett., 34 L20204.</ref> Many have a fan shape. <ref> Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:55107 1930streaksclose.jpg|Streak being affected by boulders. Arrows indicate boulders and resulting effect on streak.<br />
File:55480 2060streaksobstacles.jpg|Close view of streak showing boulders causing streak to divide<br />
</gallery><br />
<br />
Streaks may be hundreds of meters long with a width of 20 to 200 meters. Indeed, some can be over 2 kilometers long. <br />
<ref> Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<ref> Chuang, F.C.; Beyer, R.A.; Bridges, N.T. 2010. Modification of Martian Slope Streaks by Eolian Processes. Icarus, 205 154–164.</ref><br />
<ref> Baratoux, D. et al. 2006. The Role of the Wind-Transported Dust in Slope Streaks Activity: Evidence from the HRSC Data. Icarus, 183 30–45.</ref><br />
<br />
== How long do they last? ==<br />
Thanks to the many excellent cameras that we have placed in orbit over many decades, we have a history of how the Martian surface changes. Dark slope streaks are some of the most changing parts of Mars. They were discovered in Viking Orbiter pictures from the 1970,<ref name=Morris82>Morris, E.C. (1982). Aureole Deposits of the Martian Volcano Olympus Mons. ''J. Geophys. Res.,'' '''87'''(B2), 1164–1178.</ref> <ref name=Ferguson84>Ferguson,H.M.; Lucchitta, B.K. (1984). Dark Streaks on Talus Slopes, Mars in ''Reports of the Planetary Geology Program 1983, NASA Tech. Memo., TM-86246,'' pp. 188–190. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840015363_1984015363.pdf.</ref> When images from Mars Global Surveyor (MGS) and Mars Reconnaissance Orbiter (MRO) spacecraft are examined, the life history of streaks can be precisely determined.<ref>Sullivan, R. et al. (2001). Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633. </ref> <ref name=Chuang07>Chuang, F.C. et al. 2007. HiRISE Observations of Slope Streaks on Mars. 'Geophys. Res. Lett. 34 L20204.</ref> <ref>Dundas, C. 2018. HIRISE OBSERVATIONS OF NEW MARTIAN SLOPE STREAKS. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2026.pdf</ref> <ref> Malin, M.C.; Edgett, K.S. (2001). Mars Global Surveyor Mars Orbiter Camera: Interplanetary cruise through primary mission. J. Geophys. Res., 106(E10), 23,429–23,570.</ref> <br />
<ref> Edgett, K.S.; Malin, M.C.; Sullivan, R.J.; Thomas, P.; Veverka, J. (2000). Dynamic Mars: New Dark Slope Streaks Observed on Annual and Decadal Time Scales. 31st Lunar and Planetary Science Conference, Abstract #1058. http://www.lpi.usra.edu/meetings/lpsc2000/pdf/1058.pdf.</ref><br />
<br />
[[File:New Streaks Formed PIA02379.jpg|right|thumb|320px|New slope streaks formed near Apollinaris Mons between February 1998 and November 1999, as seen by Mars Orbital Camera (MOC).]]<br />
<br />
One analysis concluded that 70 streaks per day may form on the planet. The research team compared overlapping images from Mars Global Surveyor Mars Orbiter Camera that were spaced days to years apart. <ref> Aharonson, O.; Schorghofer, N.; Gerstell, M.F. (2003). Slope Streak Formation and Dust Deposition Rates on Mars. J. Geophys. Res., 108(E12), 5138, doi:10.1029/2003JE002123. </ref><br />
Dark slope streaks are constantly forming and fading. The darker ones are the youngest. Fading is accomplished by settling of bright dust in the Martian atmosphere. When researches looked at a small area (Lycus Sulci) on Mars with both Viking images and recent CTX images from the Mars Reconnaissance Orbiter, they found that the ones seen in Viking photos were gone, however, new streaks have taken their place. Their calculations indicated that slope streaks last about 40 years <ref> Bergonio, J., K. Rottas, and N. Schorghofer. 2013. Properties of martian slope streak populations: 225. Icarus: 194-199.</ref> From time to time the entire globe of Mars is enveloped in a dust storm. Many, perhaps most streaks and other features are erased during those periods.<ref> Aharonson, O.; Schorghofer, N.; Gerstell, M.F. 2003. S lope Streak Formation and Dust Deposition Rates on Mars. J. Geophys. Res., 108(E12), 5138, doi:10.1029/2003JE002123.</ref> <ref> Schorghofer, Aharonson, O.; Gerstell, M.F.; Tatsumi, L. 2007. Three Decades of Slope Streak Activity on Mars. Icarus: 191, 132–140. doi:10.1016/j.icarus.2007.04.026.</ref><br />
<br />
<gallery class="center" widths="190px" heights="180px"><br />
<br />
File:23677streakslabeled.jpg|Young and old dark slope streaks with origins labeled.<br />
<br />
File: PIA03170 fig1duststroms.jpg|Mars without a dust storm on June 2001 (on left) and with a global dust storm on July 2001 (on right), as seen by Mars Global Surveyor<br />
</gallery><br />
<br />
==What causes dark slope streaks?==<br />
Although many ideas have been put forward to explain slope streaks, the general opinion today is that they are simply avalanches of darker colored dust.<ref> Treiman, A.H.; Louge, M.Y. (2004). Martian Slope Streaks and Gullies: Origins as Dry Granular Flows. 35th Lunar and Planetary Science Conference, Abstract #1323. http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1323.pdf</ref> Nearly all of Mars is covered with a thin, bright dust. On steep slopes this layer of dust can move away and reveal a dark surface. The dark volcanic rock basalt lies under the lighter-toned dust which falls out of the atmosphere.<br />
With the long term observations from orbit, researchers have noticed that strikes by meteorites can start the process of slope formation.<ref> http://www.uahirise.org/epo/nuggets/dust-avalanche.pdf</ref> <ref>https://hirise.lpl.arizona.edu/ESP_054066_1920</ref> Moreover, even the air blast from an oncoming strike can trigger clusters of slopes to form.<ref>Kaylan J. Burleigh, Henry J. Melosh, Livio L. Tornabene, Boris Ivanov, Alfred S. McEwen, Ingrid J. Daubar. 2012. Impact air blast triggers dust avalanches on Mars Icarus: 217 (1) 194 doi:10.1016/j.icarus.2011.10.026</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:ESP 054066 1920newstreak.jpg|New dark slope streak that was triggered by an impact Location is the Arabia quadrangle<br />
</gallery><br />
<br />
==Other slope features==<br />
<br />
Several features are common on slopes on Mars. The surface of Mars is billions of years old in most <br />
places. Consequently, it has accumulated many steep slopes, especially in craters and canyons. Although streaks, gullies, and recurring slope lineae all occur on slopes, they have different origins. <br />
[[Martian gullies]] show up in certain zones. However, unlike dark slope streaks they go fairly deep into the surface and are not erased by falling dust over time. Their origin is still debated. For over a decade they were believed to be formed by recent, flowing water. <br />
<br />
<ref>Malin, M.; Edgett, K. (2000). "Evidence for recent groundwater seepage and surface runoff on Mars". Science. 288: 2330–2335.</ref><br />
<ref> Luu, K., et al. 2018. GULLY FORMATION ON THE NORTHWESTERN SLOPE OF PALIKIR CRATER, MARS 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2650.pdf</ref> <br />
<ref> Hamid, S., V. Gulick. 2018. GEOMORPHOLOGICAL ANALYSIS OF GULLIES ALONG WESTERN SLOPES OF PALIKIR CRATER. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2644.pdf</ref> <br />
<ref> Tyler Paladin, T., et al. 2018. INSIGHTS INTO THE FORMATION OF GULLIES IN ASIMOV CRATER, MARS. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2889.pdf</ref> Now, new observations suggest that gullies are being made today by chunks of dry ice moving down steep slopes in the spring. <br />
<ref> Dundas, C., S. Diniega, A. McEwen. 2015. Long-term monitoring of martian gully formation and evolution with MRO/HiRISE. Icarus: 251, 244–263</ref> <br />
<ref> Fergason, R., C. Dundas, R. Anderson. 2015. IN-DEPTH REGIONAL ASSESSMENT OF THERMOPHYSICAL PROPERTIES OF ACTIVE GULLIES ON MARS. 46th Lunar and Planetary Science Conference. 2009.pdf</ref> <br />
<ref> Dundas, C. et al. 2016. HOW WET IS RECENT MARS? INSIGHTS FROM GULLIES AND RSL. 47th Lunar and Planetary Science Conference (2016) 2327.pdf. </ref> <br />
<ref> Vincendon, M. 2015. Identification of Mars gully activity<br />
types associated with ice composition.JGR:120, 1859–1879. </ref> <br />
<ref> Raack, J.; et al. (2015). "Present-day seasonal gully activity in a south polar pit (Sisyphi Cavi) on Mars". Icarus. 251: 226–243. Bibcode:2015Icar..251..226R. doi:10.1016/j.icarus.2014.03.040. </ref> <br />
<ref> http://www.uahirise.org/ESP_044327_1375</ref> <br />
<ref> C. Pilorget, C., F. Forget. 2015. "CO2 Driven Formation of Gullies on Mars." 46th Lunar and Planetary Science Conference. 2471.pdf</ref> <br />
<ref> Pilorget, C.; Forget, F. (2016). "Formation of gullies on Mars by debris flows triggered by CO2 sublimation". Nature Geoscience. 9: 65–69. Bibcode:2016NatGe...9...65P. </ref> <br />
As the map below shows gullies and streaks are found in different areas on the planet.<br />
<gallery class="center" widths="190px" heights="180px"><br />
File:Streak Locations PIA09030.jpg|Map showing locations of gullies (brown) and streaks (pink)<br />
</gallery><br />
<br />
[[File:50858 1435gullies.jpg|600pxr|Image of gullies with main parts labeled. The main parts of a Martian gully are alcove, channel, and apron. Picture was taken by HiRISE under HiWish program.]]<br />
<br />
Like gullies and streaks, recurring slope lineae are seen on steep slopes, but they are smaller, more narrow, and straighter. Since they seem to lengthen as the temperature increases, they were believed to be involved with liquid water. <ref> McEwen, A. et al. 2011. Seasonal Flows on Warm Martian Slopes. Science, 333(6043), 740–743. doi:10.1126/science.1204816 PMID 21817049. http://www.sciencemag.org/content/333/6043/740. </ref> <br />
<ref> Mann, Adam (18 February 2014). "Strange Dark Streaks on Mars Get More and More Mysterious". Wired. Retrieved 18 February 2014. </ref> <br />
<ref> Chang, K. 2011. "Scientists Find Signs Water Is Flowing on Mars," New York Times, August 4, A13. https://www.nytimes.com/2011/08/05/science/space/05mars.html?_r=1&ref=marsplanet. </ref> <br />
<ref> HiRISE website. Seasonal Flows on Warm Martian Slopes. http://hirise.lpl.arizona.edu/sim/science-2011-aug-4.php. </ref> <br />
<ref> McEwen, A. Ojha L.; Dundas C.; Mattson, S.; Byrne S.; Wray J.; Cull S.; Murchie S. 2011. Transient Slope Lineae: Evidence for Summertime Briny Flows on Mars? 42nd Lunar and Planetary Science Conference, Abstract #2314. http://www.lpi.usra.edu/meetings/lpsc2011/pdf/2314.pdf. </ref> <br />
Nevertheless, later studies showed that very little water, if any, could be involved.<ref>Dundas, C., et al. 2017. Granular Flows at Recurring Slope Lineae on Mars Indicate a Limited Role for Liquid Water. Nature Geoscience. Nov. 20. [1].</ref> <ref>Schaefer, E., et al. 2018. A case study of recurring slope lineae (RSL) at Tivat crater: Implications for RSL origins. Icarus: In press. https://doi.org/10.1016/j.icarus.2018.07.014</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:Oblique View of Warm Season Flows in Newton Crater.jpg|Recurrent slop lineae, as seen by HiRISE<br />
</gallery><br />
<br />
== References ==<br />
{{reflist}}<br />
<br />
==See also==<br />
* [[Martian gullies]]<br />
* [[What Mars Actually Looks Like! ]] <br />
== External links ==<br />
* [[yt:_sUUKcZaTgA|Martian Ice - Jim Secosky - 16th Annual International Mars Society Convention]]</div>Akademyhttp://marspedia.org/index.php?title=User_talk:Akademy&diff=126246User talk:Akademy2018-09-23T16:57:27Z<p>Akademy: </p>
<hr />
<div>* Need template, of example of a good formatted page.<br />
** First paragraph should be a quick explanation, always in regards to Mars/The Mars Society. (For instance, the nuclear energy page explains what nuclear energy is, but also why it would be useful on Mars<br />
* "Coding standards" - e.g., title definitions should have spaces in: == title ==<br />
* Use US Spellings?</div>Akademyhttp://marspedia.org/index.php?title=Dark_slope_streaks&diff=126245Dark slope streaks2018-09-23T16:55:17Z<p>Akademy: Corrected ref pdf file name.</p>
<hr />
<div>[[File:Fan-shaped Streaks ESP 012410 1835cropped.jpg|300px|right|Dark slope streaks, as seen by HiRISE]]<br />
Dark slope streaks are found on Mars on dust-covered slopes often near the equator.<br />
<br />
==Appearance==<br />
<br />
Perhaps, some of the prettiest landscapes on Mars, dark slope streaks are found on dust-covered slopes, particular near the equator.<ref name=Chuang10>Chuang, F.C.; Beyer, R.A.; Bridges, N.T. (2010). Modification of Martian Slope Streaks by Eolian Processes. ''Icarus,'' '''205''' 154–164.</ref> However, much of their beauty is from the way images are processed. Scientists set the darkest part of the image to black to more easily see detail, but this darkest part is unlikely to actually be black. Streaks are actually only about 10% darker than their surroundings. <ref>Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:PIA22240slopstreaks.jpg | Close view of dark slope streaks<br />
</gallery><br />
<br />
Typically, streaks begin at a small point high on a steep slope, such as a crater wall.<ref name= Schorghofer02>Schorghofer, N.; Aharonson, O.; Khatiwala, S. 2002. Slope Streaks on Mars: Correlations with Surface Properties and the Potential Role of Water. ''Geophys. Res. Lett.,'' '''29'''(23), 2126.</ref> And then they greatly widen and sometimes divide into finger-like extensions (digitation). Obstacles, such as boulders, may cause an individual streak to split into two separate streaks or eventually form a braided (anastomosing) pattern.<ref> Chuang, F.C. et al. 2007. HiRISE Observations of Slope Streaks on Mars. Geophys. Res. Lett., 34 L20204.</ref> Many have a fan shape. <ref> Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:55107 1930streaksclose.jpg|Streak being affected by boulders. Arrows indicate boulders and resulting effect on streak.<br />
File:55480 2060streaksobstacles.jpg|Close view of streak showing boulders causing streak to divide<br />
</gallery><br />
<br />
Streaks may be hundreds of meters long with a width of 20 to 200 meters. Indeed, some can be over 2 kilometers long. <br />
<ref> Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<ref> Chuang, F.C.; Beyer, R.A.; Bridges, N.T. 2010. Modification of Martian Slope Streaks by Eolian Processes. Icarus, 205 154–164.</ref><br />
<ref> Baratoux, D. et al. 2006. The Role of the Wind-Transported Dust in Slope Streaks Activity: Evidence from the HRSC Data. Icarus, 183 30–45.</ref><br />
<br />
== How long do they last? ==<br />
Thanks to the many excellent cameras that we have placed in orbit over many decades, we have a history of how the Martian surface changes. Dark slope streaks are some of the most changing parts of Mars. They were discovered in Viking Orbiter pictures from the 1970,<ref name=Morris82>Morris, E.C. (1982). Aureole Deposits of the Martian Volcano Olympus Mons. ''J. Geophys. Res.,'' '''87'''(B2), 1164–1178.</ref> <ref name=Ferguson84>Ferguson,H.M.; Lucchitta, B.K. (1984). Dark Streaks on Talus Slopes, Mars in ''Reports of the Planetary Geology Program 1983, NASA Tech. Memo., TM-86246,'' pp. 188–190. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840015363_1984015363.pdf.</ref> When images from Mars Global Surveyor (MGS) and Mars Reconnaissance Orbiter (MRO) spacecraft are examined, the life history of streaks can be precisely determined.<ref>Sullivan, R. et al. (2001). Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633. </ref> <ref name=Chuang07>Chuang, F.C. et al. 2007. HiRISE Observations of Slope Streaks on Mars. 'Geophys. Res. Lett. 34 L20204.</ref> <ref>Dundas, C. 2018. HIRISE OBSERVATIONS OF NEW MARTIAN SLOPE STREAKS. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2026.pdf</ref> <ref> Malin, M.C.; Edgett, K.S. (2001). Mars Global Surveyor Mars Orbiter Camera: Interplanetary cruise through primary mission. J. Geophys. Res., 106(E10), 23,429–23,570.</ref> <br />
<ref> Edgett, K.S.; Malin, M.C.; Sullivan, R.J.; Thomas, P.; Veverka, J. (2000). Dynamic Mars: New Dark Slope Streaks Observed on Annual and Decadal Time Scales. 31st Lunar and Planetary Science Conference, Abstract #1058. http://www.lpi.usra.edu/meetings/lpsc2000/pdf/1058.pdf.</ref><br />
<br />
[[File:New Streaks Formed PIA02379.jpg|right|thumb|320px|New slope streaks formed near Apollinaris Mons between February 1998 and November 1999, as seen by Mars Orbital Camera (MOC).]]<br />
<br />
One analysis concluded that 70 streaks per day may form on the planet. The research team compared overlapping images from Mars Global Surveyor Mars Orbiter Camera that were spaced days to years apart. <ref> Aharonson, O.; Schorghofer, N.; Gerstell, M.F. (2003). Slope Streak Formation and Dust Deposition Rates on Mars. J. Geophys. Res., 108(E12), 5138, doi:10.1029/2003JE002123. </ref><br />
Dark slope streaks are constantly forming and fading. The darker ones are the youngest. Fading is accomplished by settling of bright dust in the Martian atmosphere. When researches looked at a small area (Lycus Sulci) on Mars with both Viking images and recent CTX images from the Mars Reconnaissance Orbiter, they found that the ones seen in Viking photos were gone, however, new streaks have taken their place. Their calculations indicated that slope streaks last about 40 years <ref> Bergonio, J., K. Rottas, and N. Schorghofer. 2013. Properties of martian slope streak populations: 225. Icarus: 194-199.</ref> From time to time the entire globe of Mars is enveloped in a dust storm. Many, perhaps most streaks and other features are erased during those periods.<ref> Aharonson, O.; Schorghofer, N.; Gerstell, M.F. 2003. S lope Streak Formation and Dust Deposition Rates on Mars. J. Geophys. Res., 108(E12), 5138, doi:10.1029/2003JE002123.</ref> <ref> Schorghofer, Aharonson, O.; Gerstell, M.F.; Tatsumi, L. 2007. Three Decades of Slope Streak Activity on Mars. Icarus: 191, 132–140. doi:10.1016/j.icarus.2007.04.026.</ref><br />
<br />
<gallery class="center" widths="190px" heights="180px"><br />
<br />
File:23677streakslabeled.jpg|Young and old dark slope streaks with origins labeled.<br />
<br />
File: PIA03170 fig1duststroms.jpg|Mars without a dust storm on June 2001 (on left) and with a global dust storm on July 2001 (on right), as seen by Mars Global Surveyor<br />
</gallery><br />
<br />
==What causes dark slope streaks?==<br />
Although many ideas have been put forward to explain slope streaks, the general opinion today is that they are simply avalanches of bright dust.<ref> Treiman, A.H.; Louge, M.Y. (2004). Martian Slope Streaks and Gullies: Origins as Dry Granular Flows. 35th Lunar and Planetary Science Conference, Abstract #1323. http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1323.pdf</ref> Nearly all of Mars is covered with a thin, bright dust. On steep slopes this layer of dust can move away and reveal a dark surface. The dark volcanic rock basalt lies under the lighter-toned dust which falls out of the atmosphere.<br />
With the long term observations from orbit, researchers have noticed that strikes by meteorites can start the process of slope formation.<ref> http://www.uahirise.org/epo/nuggets/dust-avalanche.pdf</ref> <ref>https://hirise.lpl.arizona.edu/ESP_054066_1920</ref> Moreover, even the air blast from an oncoming strike can trigger clusters of slopes to form.<ref>Kaylan J. Burleigh, Henry J. Melosh, Livio L. Tornabene, Boris Ivanov, Alfred S. McEwen, Ingrid J. Daubar. 2012. Impact air blast triggers dust avalanches on Mars Icarus: 217 (1) 194 doi:10.1016/j.icarus.2011.10.026</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:ESP 054066 1920newstreak.jpg|New dark slope streak that was triggered by an impact Location is the Arabia quadrangle<br />
</gallery><br />
<br />
==Other slope features==<br />
<br />
Several features are common on slopes on Mars. The surface of Mars is billions of years old in most <br />
places. Consequently, it has accumulated many steep slopes, especially in craters and canyons. Although streaks, gullies, and recurring slope lineae all occur on slopes, they have different origins. <br />
[[Martian gullies]] show up in certain zones. However, unlike dark slope streaks they go fairly deep into the surface and are not erased by falling dust over time. Their origin is still debated. For over a decade they were believed to be formed by recent, flowing water. <br />
<br />
<ref>Malin, M.; Edgett, K. (2000). "Evidence for recent groundwater seepage and surface runoff on Mars". Science. 288: 2330–2335.</ref><br />
<ref> Luu, K., et al. 2018. GULLY FORMATION ON THE NORTHWESTERN SLOPE OF PALIKIR CRATER, MARS 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2650.pdf</ref> <br />
<ref> Hamid, S., V. Gulick. 2018. GEOMORPHOLOGICAL ANALYSIS OF GULLIES ALONG WESTERN SLOPES OF PALIKIR CRATER. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2644.pdf</ref> <br />
<ref> Tyler Paladin, T., et al. 2018. INSIGHTS INTO THE FORMATION OF GULLIES IN ASIMOV CRATER, MARS. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2889.pdf</ref> Now, new observations suggest that gullies are being made today by chunks of dry ice moving down steep slopes in the spring. <br />
<ref> Dundas, C., S. Diniega, A. McEwen. 2015. Long-term monitoring of martian gully formation and evolution with MRO/HiRISE. Icarus: 251, 244–263</ref> <br />
<ref> Fergason, R., C. Dundas, R. Anderson. 2015. IN-DEPTH REGIONAL ASSESSMENT OF THERMOPHYSICAL PROPERTIES OF ACTIVE GULLIES ON MARS. 46th Lunar and Planetary Science Conference. 2009.pdf</ref> <br />
<ref> Dundas, C. et al. 2016. HOW WET IS RECENT MARS? INSIGHTS FROM GULLIES AND RSL. 47th Lunar and Planetary Science Conference (2016) 2327.pdf. </ref> <br />
<ref> Vincendon, M. 2015. Identification of Mars gully activity<br />
types associated with ice composition.JGR:120, 1859–1879. </ref> <br />
<ref> Raack, J.; et al. (2015). "Present-day seasonal gully activity in a south polar pit (Sisyphi Cavi) on Mars". Icarus. 251: 226–243. Bibcode:2015Icar..251..226R. doi:10.1016/j.icarus.2014.03.040. </ref> <br />
<ref> http://www.uahirise.org/ESP_044327_1375</ref> <br />
<ref> C. Pilorget, C., F. Forget. 2015. "CO2 Driven Formation of Gullies on Mars." 46th Lunar and Planetary Science Conference. 2471.pdf</ref> <br />
<ref> Pilorget, C.; Forget, F. (2016). "Formation of gullies on Mars by debris flows triggered by CO2 sublimation". Nature Geoscience. 9: 65–69. Bibcode:2016NatGe...9...65P. </ref> <br />
As the map below shows gullies and streaks are found in different areas on the planet.<br />
<gallery class="center" widths="190px" heights="180px"><br />
File:Streak Locations PIA09030.jpg|Map showing locations of gullies (brown) and streaks (pink)<br />
</gallery><br />
<br />
[[File:50858 1435gullies.jpg|600pxr|Image of gullies with main parts labeled. The main parts of a Martian gully are alcove, channel, and apron. Picture was taken by HiRISE under HiWish program.]]<br />
<br />
Like gullies and streaks, recurring slope lineae are seen on steep slopes, but they are smaller, more narrow, and straighter. Since they seem to lengthen as the temperature increases, they were believed to be involved with liquid water. <ref> McEwen, A. et al. 2011. Seasonal Flows on Warm Martian Slopes. Science, 333(6043), 740–743. doi:10.1126/science.1204816 PMID 21817049. http://www.sciencemag.org/content/333/6043/740. </ref> <br />
<ref> Mann, Adam (18 February 2014). "Strange Dark Streaks on Mars Get More and More Mysterious". Wired. Retrieved 18 February 2014. </ref> <br />
<ref> Chang, K. 2011. "Scientists Find Signs Water Is Flowing on Mars," New York Times, August 4, A13. https://www.nytimes.com/2011/08/05/science/space/05mars.html?_r=1&ref=marsplanet. </ref> <br />
<ref> HiRISE website. Seasonal Flows on Warm Martian Slopes. http://hirise.lpl.arizona.edu/sim/science-2011-aug-4.php. </ref> <br />
<ref> McEwen, A. Ojha L.; Dundas C.; Mattson, S.; Byrne S.; Wray J.; Cull S.; Murchie S. 2011. Transient Slope Lineae: Evidence for Summertime Briny Flows on Mars? 42nd Lunar and Planetary Science Conference, Abstract #2314. http://www.lpi.usra.edu/meetings/lpsc2011/pdf/2314.pdf. </ref> <br />
Nevertheless, later studies showed that very little water, if any, could be involved.<ref>Dundas, C., et al. 2017. Granular Flows at Recurring Slope Lineae on Mars Indicate a Limited Role for Liquid Water. Nature Geoscience. Nov. 20. [1].</ref> <ref>Schaefer, E., et al. 2018. A case study of recurring slope lineae (RSL) at Tivat crater: Implications for RSL origins. Icarus: In press. https://doi.org/10.1016/j.icarus.2018.07.014</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:Oblique View of Warm Season Flows in Newton Crater.jpg|Recurrent slop lineae, as seen by HiRISE<br />
</gallery><br />
<br />
== References ==<br />
{{reflist}}<br />
<br />
==See also==<br />
* [[Martian gullies]]<br />
* [[What Mars Actually Looks Like! ]] <br />
== External links ==<br />
* [[yt:_sUUKcZaTgA|Martian Ice - Jim Secosky - 16th Annual International Mars Society Convention]]</div>Akademyhttp://marspedia.org/index.php?title=Dark_slope_streaks&diff=126244Dark slope streaks2018-09-23T16:54:28Z<p>Akademy: Tweak photo size</p>
<hr />
<div>[[File:Fan-shaped Streaks ESP 012410 1835cropped.jpg|300px|right|Dark slope streaks, as seen by HiRISE]]<br />
Dark slope streaks are found on Mars on dust-covered slopes often near the equator.<br />
<br />
==Appearance==<br />
<br />
Perhaps, some of the prettiest landscapes on Mars, dark slope streaks are found on dust-covered slopes, particular near the equator.<ref name=Chuang10>Chuang, F.C.; Beyer, R.A.; Bridges, N.T. (2010). Modification of Martian Slope Streaks by Eolian Processes. ''Icarus,'' '''205''' 154–164.</ref> However, much of their beauty is from the way images are processed. Scientists set the darkest part of the image to black to more easily see detail, but this darkest part is unlikely to actually be black. Streaks are actually only about 10% darker than their surroundings. <ref>Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:PIA22240slopstreaks.jpg | Close view of dark slope streaks<br />
</gallery><br />
<br />
Typically, streaks begin at a small point high on a steep slope, such as a crater wall.<ref name= Schorghofer02>Schorghofer, N.; Aharonson, O.; Khatiwala, S. 2002. Slope Streaks on Mars: Correlations with Surface Properties and the Potential Role of Water. ''Geophys. Res. Lett.,'' '''29'''(23), 2126.</ref> And then they greatly widen and sometimes divide into finger-like extensions (digitation). Obstacles, such as boulders, may cause an individual streak to split into two separate streaks or eventually form a braided (anastomosing) pattern.<ref> Chuang, F.C. et al. 2007. HiRISE Observations of Slope Streaks on Mars. Geophys. Res. Lett., 34 L20204.</ref> Many have a fan shape. <ref> Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:55107 1930streaksclose.jpg|Streak being affected by boulders. Arrows indicate boulders and resulting effect on streak.<br />
File:55480 2060streaksobstacles.jpg|Close view of streak showing boulders causing streak to divide<br />
</gallery><br />
<br />
Streaks may be hundreds of meters long with a width of 20 to 200 meters. Indeed, some can be over 2 kilometers long. <br />
<ref> Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<ref> Chuang, F.C.; Beyer, R.A.; Bridges, N.T. 2010. Modification of Martian Slope Streaks by Eolian Processes. Icarus, 205 154–164.</ref><br />
<ref> Baratoux, D. et al. 2006. The Role of the Wind-Transported Dust in Slope Streaks Activity: Evidence from the HRSC Data. Icarus, 183 30–45.</ref><br />
<br />
== How long do they last? ==<br />
Thanks to the many excellent cameras that we have placed in orbit over many decades, we have a history of how the Martian surface changes. Dark slope streaks are some of the most changing parts of Mars. They were discovered in Viking Orbiter pictures from the 1970,<ref name=Morris82>Morris, E.C. (1982). Aureole Deposits of the Martian Volcano Olympus Mons. ''J. Geophys. Res.,'' '''87'''(B2), 1164–1178.</ref> <ref name=Ferguson84>Ferguson,H.M.; Lucchitta, B.K. (1984). Dark Streaks on Talus Slopes, Mars in ''Reports of the Planetary Geology Program 1983, NASA Tech. Memo., TM-86246,'' pp. 188–190. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840015363_1984015363.pdf.</ref> When images from Mars Global Surveyor (MGS) and Mars Reconnaissance Orbiter (MRO) spacecraft are examined, the life history of streaks can be precisely determined.<ref>Sullivan, R. et al. (2001). Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633. </ref> <ref name=Chuang07>Chuang, F.C. et al. 2007. HiRISE Observations of Slope Streaks on Mars. 'Geophys. Res. Lett. 34 L20204.</ref> <ref>Dundas, C. 2018. HIRISE OBSERVATIONS OF NEW MARTIAN SLOPE STREAKS. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2026.pdf</ref> <ref> Malin, M.C.; Edgett, K.S. (2001). Mars Global Surveyor Mars Orbiter Camera: Interplanetary cruise through primary mission. J. Geophys. Res., 106(E10), 23,429–23,570.</ref> <br />
<ref> Edgett, K.S.; Malin, M.C.; Sullivan, R.J.; Thomas, P.; Veverka, J. (2000). Dynamic Mars: New Dark Slope Streaks Observed on Annual and Decadal Time Scales. 31st Lunar and Planetary Science Conference, Abstract #1058. http://www.lpi.usra.edu/meetings/lpsc2000/pdf/1058.pdf.</ref><br />
<br />
[[File:New Streaks Formed PIA02379.jpg|right|thumb|320px|New slope streaks formed near Apollinaris Mons between February 1998 and November 1999, as seen by Mars Orbital Camera (MOC).]]<br />
<br />
One analysis concluded that 70 streaks per day may form on the planet. The research team compared overlapping images from Mars Global Surveyor Mars Orbiter Camera that were spaced days to years apart. <ref> Aharonson, O.; Schorghofer, N.; Gerstell, M.F. (2003). Slope Streak Formation and Dust Deposition Rates on Mars. J. Geophys. Res., 108(E12), 5138, doi:10.1029/2003JE002123. </ref><br />
Dark slope streaks are constantly forming and fading. The darker ones are the youngest. Fading is accomplished by settling of bright dust in the Martian atmosphere. When researches looked at a small area (Lycus Sulci) on Mars with both Viking images and recent CTX images from the Mars Reconnaissance Orbiter, they found that the ones seen in Viking photos were gone, however, new streaks have taken their place. Their calculations indicated that slope streaks last about 40 years <ref> Bergonio, J., K. Rottas, and N. Schorghofer. 2013. Properties of martian slope streak populations: 225. Icarus: 194-199.</ref> From time to time the entire globe of Mars is enveloped in a dust storm. Many, perhaps most streaks and other features are erased during those periods.<ref> Aharonson, O.; Schorghofer, N.; Gerstell, M.F. 2003. S lope Streak Formation and Dust Deposition Rates on Mars. J. Geophys. Res., 108(E12), 5138, doi:10.1029/2003JE002123.</ref> <ref> Schorghofer, Aharonson, O.; Gerstell, M.F.; Tatsumi, L. 2007. Three Decades of Slope Streak Activity on Mars. Icarus: 191, 132–140. doi:10.1016/j.icarus.2007.04.026.</ref><br />
<br />
<gallery class="center" widths="190px" heights="180px"><br />
<br />
File:23677streakslabeled.jpg|Young and old dark slope streaks with origins labeled.<br />
<br />
File: PIA03170 fig1duststroms.jpg|Mars without a dust storm on June 2001 (on left) and with a global dust storm on July 2001 (on right), as seen by Mars Global Surveyor<br />
</gallery><br />
<br />
==What causes dark slope streaks?==<br />
Although many ideas have been put forward to explain slope streaks, the general opinion today is that they are simply avalanches of bright dust.<ref> Treiman, A.H.; Louge, M.Y. (2004). Martian Slope Streaks and Gullies: Origins as Dry Granular Flows. 35th Lunar and Planetary Science Conference, Abstract #1323. http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1323.p</ref> Nearly all of Mars is covered with a thin, bright dust. On steep slopes this layer of dust can move away and reveal a dark surface. The dark volcanic rock basalt lies under the lighter-toned dust which falls out of the atmosphere.<br />
With the long term observations from orbit, researchers have noticed that strikes by meteorites can start the process of slope formation.<ref> http://www.uahirise.org/epo/nuggets/dust-avalanche.pdf</ref> <ref>https://hirise.lpl.arizona.edu/ESP_054066_1920</ref> Moreover, even the air blast from an oncoming strike can trigger clusters of slopes to form.<ref>Kaylan J. Burleigh, Henry J. Melosh, Livio L. Tornabene, Boris Ivanov, Alfred S. McEwen, Ingrid J. Daubar. 2012. Impact air blast triggers dust avalanches on Mars Icarus: 217 (1) 194 doi:10.1016/j.icarus.2011.10.026</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:ESP 054066 1920newstreak.jpg|New dark slope streak that was triggered by an impact Location is the Arabia quadrangle<br />
</gallery><br />
<br />
==Other slope features==<br />
<br />
Several features are common on slopes on Mars. The surface of Mars is billions of years old in most <br />
places. Consequently, it has accumulated many steep slopes, especially in craters and canyons. Although streaks, gullies, and recurring slope lineae all occur on slopes, they have different origins. <br />
[[Martian gullies]] show up in certain zones. However, unlike dark slope streaks they go fairly deep into the surface and are not erased by falling dust over time. Their origin is still debated. For over a decade they were believed to be formed by recent, flowing water. <br />
<br />
<ref>Malin, M.; Edgett, K. (2000). "Evidence for recent groundwater seepage and surface runoff on Mars". Science. 288: 2330–2335.</ref><br />
<ref> Luu, K., et al. 2018. GULLY FORMATION ON THE NORTHWESTERN SLOPE OF PALIKIR CRATER, MARS 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2650.pdf</ref> <br />
<ref> Hamid, S., V. Gulick. 2018. GEOMORPHOLOGICAL ANALYSIS OF GULLIES ALONG WESTERN SLOPES OF PALIKIR CRATER. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2644.pdf</ref> <br />
<ref> Tyler Paladin, T., et al. 2018. INSIGHTS INTO THE FORMATION OF GULLIES IN ASIMOV CRATER, MARS. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2889.pdf</ref> Now, new observations suggest that gullies are being made today by chunks of dry ice moving down steep slopes in the spring. <br />
<ref> Dundas, C., S. Diniega, A. McEwen. 2015. Long-term monitoring of martian gully formation and evolution with MRO/HiRISE. Icarus: 251, 244–263</ref> <br />
<ref> Fergason, R., C. Dundas, R. Anderson. 2015. IN-DEPTH REGIONAL ASSESSMENT OF THERMOPHYSICAL PROPERTIES OF ACTIVE GULLIES ON MARS. 46th Lunar and Planetary Science Conference. 2009.pdf</ref> <br />
<ref> Dundas, C. et al. 2016. HOW WET IS RECENT MARS? INSIGHTS FROM GULLIES AND RSL. 47th Lunar and Planetary Science Conference (2016) 2327.pdf. </ref> <br />
<ref> Vincendon, M. 2015. Identification of Mars gully activity<br />
types associated with ice composition.JGR:120, 1859–1879. </ref> <br />
<ref> Raack, J.; et al. (2015). "Present-day seasonal gully activity in a south polar pit (Sisyphi Cavi) on Mars". Icarus. 251: 226–243. Bibcode:2015Icar..251..226R. doi:10.1016/j.icarus.2014.03.040. </ref> <br />
<ref> http://www.uahirise.org/ESP_044327_1375</ref> <br />
<ref> C. Pilorget, C., F. Forget. 2015. "CO2 Driven Formation of Gullies on Mars." 46th Lunar and Planetary Science Conference. 2471.pdf</ref> <br />
<ref> Pilorget, C.; Forget, F. (2016). "Formation of gullies on Mars by debris flows triggered by CO2 sublimation". Nature Geoscience. 9: 65–69. Bibcode:2016NatGe...9...65P. </ref> <br />
As the map below shows gullies and streaks are found in different areas on the planet.<br />
<gallery class="center" widths="190px" heights="180px"><br />
File:Streak Locations PIA09030.jpg|Map showing locations of gullies (brown) and streaks (pink)<br />
</gallery><br />
<br />
[[File:50858 1435gullies.jpg|600pxr|Image of gullies with main parts labeled. The main parts of a Martian gully are alcove, channel, and apron. Picture was taken by HiRISE under HiWish program.]]<br />
<br />
Like gullies and streaks, recurring slope lineae are seen on steep slopes, but they are smaller, more narrow, and straighter. Since they seem to lengthen as the temperature increases, they were believed to be involved with liquid water. <ref> McEwen, A. et al. 2011. Seasonal Flows on Warm Martian Slopes. Science, 333(6043), 740–743. doi:10.1126/science.1204816 PMID 21817049. http://www.sciencemag.org/content/333/6043/740. </ref> <br />
<ref> Mann, Adam (18 February 2014). "Strange Dark Streaks on Mars Get More and More Mysterious". Wired. Retrieved 18 February 2014. </ref> <br />
<ref> Chang, K. 2011. "Scientists Find Signs Water Is Flowing on Mars," New York Times, August 4, A13. https://www.nytimes.com/2011/08/05/science/space/05mars.html?_r=1&ref=marsplanet. </ref> <br />
<ref> HiRISE website. Seasonal Flows on Warm Martian Slopes. http://hirise.lpl.arizona.edu/sim/science-2011-aug-4.php. </ref> <br />
<ref> McEwen, A. Ojha L.; Dundas C.; Mattson, S.; Byrne S.; Wray J.; Cull S.; Murchie S. 2011. Transient Slope Lineae: Evidence for Summertime Briny Flows on Mars? 42nd Lunar and Planetary Science Conference, Abstract #2314. http://www.lpi.usra.edu/meetings/lpsc2011/pdf/2314.pdf. </ref> <br />
Nevertheless, later studies showed that very little water, if any, could be involved.<ref>Dundas, C., et al. 2017. Granular Flows at Recurring Slope Lineae on Mars Indicate a Limited Role for Liquid Water. Nature Geoscience. Nov. 20. [1].</ref> <ref>Schaefer, E., et al. 2018. A case study of recurring slope lineae (RSL) at Tivat crater: Implications for RSL origins. Icarus: In press. https://doi.org/10.1016/j.icarus.2018.07.014</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:Oblique View of Warm Season Flows in Newton Crater.jpg|Recurrent slop lineae, as seen by HiRISE<br />
</gallery><br />
<br />
== References ==<br />
{{reflist}}<br />
<br />
==See also==<br />
* [[Martian gullies]]<br />
* [[What Mars Actually Looks Like! ]] <br />
== External links ==<br />
* [[yt:_sUUKcZaTgA|Martian Ice - Jim Secosky - 16th Annual International Mars Society Convention]]</div>Akademyhttp://marspedia.org/index.php?title=Dark_slope_streaks&diff=126243Dark slope streaks2018-09-23T16:49:23Z<p>Akademy: Improving opening text</p>
<hr />
<div>[[File:Fan-shaped Streaks ESP 012410 1835cropped.jpg|600pxr|right|Dark slope streaks, as seen by HiRISE]]<br />
Dark slope streaks are found on Mars on dust-covered slopes often near the equator.<br />
<br />
==Appearance==<br />
<br />
Perhaps, some of the prettiest landscapes on Mars, dark slope streaks are found on dust-covered slopes, particular near the equator.<ref name=Chuang10>Chuang, F.C.; Beyer, R.A.; Bridges, N.T. (2010). Modification of Martian Slope Streaks by Eolian Processes. ''Icarus,'' '''205''' 154–164.</ref> However, much of their beauty is from the way images are processed. Scientists set the darkest part of the image to black to more easily see detail, but this darkest part is unlikely to actually be black. Streaks are actually only about 10% darker than their surroundings. <ref>Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:PIA22240slopstreaks.jpg | Close view of dark slope streaks<br />
</gallery><br />
<br />
Typically, streaks begin at a small point high on a steep slope, such as a crater wall.<ref name= Schorghofer02>Schorghofer, N.; Aharonson, O.; Khatiwala, S. 2002. Slope Streaks on Mars: Correlations with Surface Properties and the Potential Role of Water. ''Geophys. Res. Lett.,'' '''29'''(23), 2126.</ref> And then they greatly widen and sometimes divide into finger-like extensions (digitation). Obstacles, such as boulders, may cause an individual streak to split into two separate streaks or eventually form a braided (anastomosing) pattern.<ref> Chuang, F.C. et al. 2007. HiRISE Observations of Slope Streaks on Mars. Geophys. Res. Lett., 34 L20204.</ref> Many have a fan shape. <ref> Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:55107 1930streaksclose.jpg|Streak being affected by boulders. Arrows indicate boulders and resulting effect on streak.<br />
File:55480 2060streaksobstacles.jpg|Close view of streak showing boulders causing streak to divide<br />
</gallery><br />
<br />
Streaks may be hundreds of meters long with a width of 20 to 200 meters. Indeed, some can be over 2 kilometers long. <br />
<ref> Sullivan, R. et al. 2001. Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633.</ref><br />
<ref> Chuang, F.C.; Beyer, R.A.; Bridges, N.T. 2010. Modification of Martian Slope Streaks by Eolian Processes. Icarus, 205 154–164.</ref><br />
<ref> Baratoux, D. et al. 2006. The Role of the Wind-Transported Dust in Slope Streaks Activity: Evidence from the HRSC Data. Icarus, 183 30–45.</ref><br />
<br />
== How long do they last? ==<br />
Thanks to the many excellent cameras that we have placed in orbit over many decades, we have a history of how the Martian surface changes. Dark slope streaks are some of the most changing parts of Mars. They were discovered in Viking Orbiter pictures from the 1970,<ref name=Morris82>Morris, E.C. (1982). Aureole Deposits of the Martian Volcano Olympus Mons. ''J. Geophys. Res.,'' '''87'''(B2), 1164–1178.</ref> <ref name=Ferguson84>Ferguson,H.M.; Lucchitta, B.K. (1984). Dark Streaks on Talus Slopes, Mars in ''Reports of the Planetary Geology Program 1983, NASA Tech. Memo., TM-86246,'' pp. 188–190. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19840015363_1984015363.pdf.</ref> When images from Mars Global Surveyor (MGS) and Mars Reconnaissance Orbiter (MRO) spacecraft are examined, the life history of streaks can be precisely determined.<ref>Sullivan, R. et al. (2001). Mass Movement Slope Streaks Imaged by the Mars Orbiter Camera. J. Geophys. Res., 106(E10), 23,607–23,633. </ref> <ref name=Chuang07>Chuang, F.C. et al. 2007. HiRISE Observations of Slope Streaks on Mars. 'Geophys. Res. Lett. 34 L20204.</ref> <ref>Dundas, C. 2018. HIRISE OBSERVATIONS OF NEW MARTIAN SLOPE STREAKS. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2026.pdf</ref> <ref> Malin, M.C.; Edgett, K.S. (2001). Mars Global Surveyor Mars Orbiter Camera: Interplanetary cruise through primary mission. J. Geophys. Res., 106(E10), 23,429–23,570.</ref> <br />
<ref> Edgett, K.S.; Malin, M.C.; Sullivan, R.J.; Thomas, P.; Veverka, J. (2000). Dynamic Mars: New Dark Slope Streaks Observed on Annual and Decadal Time Scales. 31st Lunar and Planetary Science Conference, Abstract #1058. http://www.lpi.usra.edu/meetings/lpsc2000/pdf/1058.pdf.</ref><br />
<br />
[[File:New Streaks Formed PIA02379.jpg|right|thumb|320px|New slope streaks formed near Apollinaris Mons between February 1998 and November 1999, as seen by Mars Orbital Camera (MOC).]]<br />
<br />
One analysis concluded that 70 streaks per day may form on the planet. The research team compared overlapping images from Mars Global Surveyor Mars Orbiter Camera that were spaced days to years apart. <ref> Aharonson, O.; Schorghofer, N.; Gerstell, M.F. (2003). Slope Streak Formation and Dust Deposition Rates on Mars. J. Geophys. Res., 108(E12), 5138, doi:10.1029/2003JE002123. </ref><br />
Dark slope streaks are constantly forming and fading. The darker ones are the youngest. Fading is accomplished by settling of bright dust in the Martian atmosphere. When researches looked at a small area (Lycus Sulci) on Mars with both Viking images and recent CTX images from the Mars Reconnaissance Orbiter, they found that the ones seen in Viking photos were gone, however, new streaks have taken their place. Their calculations indicated that slope streaks last about 40 years <ref> Bergonio, J., K. Rottas, and N. Schorghofer. 2013. Properties of martian slope streak populations: 225. Icarus: 194-199.</ref> From time to time the entire globe of Mars is enveloped in a dust storm. Many, perhaps most streaks and other features are erased during those periods.<ref> Aharonson, O.; Schorghofer, N.; Gerstell, M.F. 2003. S lope Streak Formation and Dust Deposition Rates on Mars. J. Geophys. Res., 108(E12), 5138, doi:10.1029/2003JE002123.</ref> <ref> Schorghofer, Aharonson, O.; Gerstell, M.F.; Tatsumi, L. 2007. Three Decades of Slope Streak Activity on Mars. Icarus: 191, 132–140. doi:10.1016/j.icarus.2007.04.026.</ref><br />
<br />
<gallery class="center" widths="190px" heights="180px"><br />
<br />
File:23677streakslabeled.jpg|Young and old dark slope streaks with origins labeled.<br />
<br />
File: PIA03170 fig1duststroms.jpg|Mars without a dust storm on June 2001 (on left) and with a global dust storm on July 2001 (on right), as seen by Mars Global Surveyor<br />
</gallery><br />
<br />
==What causes dark slope streaks?==<br />
Although many ideas have been put forward to explain slope streaks, the general opinion today is that they are simply avalanches of bright dust.<ref> Treiman, A.H.; Louge, M.Y. (2004). Martian Slope Streaks and Gullies: Origins as Dry Granular Flows. 35th Lunar and Planetary Science Conference, Abstract #1323. http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1323.p</ref> Nearly all of Mars is covered with a thin, bright dust. On steep slopes this layer of dust can move away and reveal a dark surface. The dark volcanic rock basalt lies under the lighter-toned dust which falls out of the atmosphere.<br />
With the long term observations from orbit, researchers have noticed that strikes by meteorites can start the process of slope formation.<ref> http://www.uahirise.org/epo/nuggets/dust-avalanche.pdf</ref> <ref>https://hirise.lpl.arizona.edu/ESP_054066_1920</ref> Moreover, even the air blast from an oncoming strike can trigger clusters of slopes to form.<ref>Kaylan J. Burleigh, Henry J. Melosh, Livio L. Tornabene, Boris Ivanov, Alfred S. McEwen, Ingrid J. Daubar. 2012. Impact air blast triggers dust avalanches on Mars Icarus: 217 (1) 194 doi:10.1016/j.icarus.2011.10.026</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:ESP 054066 1920newstreak.jpg|New dark slope streak that was triggered by an impact Location is the Arabia quadrangle<br />
</gallery><br />
<br />
==Other slope features==<br />
<br />
Several features are common on slopes on Mars. The surface of Mars is billions of years old in most <br />
places. Consequently, it has accumulated many steep slopes, especially in craters and canyons. Although streaks, gullies, and recurring slope lineae all occur on slopes, they have different origins. <br />
[[Martian gullies]] show up in certain zones. However, unlike dark slope streaks they go fairly deep into the surface and are not erased by falling dust over time. Their origin is still debated. For over a decade they were believed to be formed by recent, flowing water. <br />
<br />
<ref>Malin, M.; Edgett, K. (2000). "Evidence for recent groundwater seepage and surface runoff on Mars". Science. 288: 2330–2335.</ref><br />
<ref> Luu, K., et al. 2018. GULLY FORMATION ON THE NORTHWESTERN SLOPE OF PALIKIR CRATER, MARS 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2650.pdf</ref> <br />
<ref> Hamid, S., V. Gulick. 2018. GEOMORPHOLOGICAL ANALYSIS OF GULLIES ALONG WESTERN SLOPES OF PALIKIR CRATER. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2644.pdf</ref> <br />
<ref> Tyler Paladin, T., et al. 2018. INSIGHTS INTO THE FORMATION OF GULLIES IN ASIMOV CRATER, MARS. 49th Lunar and Planetary Science Conference 2018 (LPI Contrib. No. 2083). 2889.pdf</ref> Now, new observations suggest that gullies are being made today by chunks of dry ice moving down steep slopes in the spring. <br />
<ref> Dundas, C., S. Diniega, A. McEwen. 2015. Long-term monitoring of martian gully formation and evolution with MRO/HiRISE. Icarus: 251, 244–263</ref> <br />
<ref> Fergason, R., C. Dundas, R. Anderson. 2015. IN-DEPTH REGIONAL ASSESSMENT OF THERMOPHYSICAL PROPERTIES OF ACTIVE GULLIES ON MARS. 46th Lunar and Planetary Science Conference. 2009.pdf</ref> <br />
<ref> Dundas, C. et al. 2016. HOW WET IS RECENT MARS? INSIGHTS FROM GULLIES AND RSL. 47th Lunar and Planetary Science Conference (2016) 2327.pdf. </ref> <br />
<ref> Vincendon, M. 2015. Identification of Mars gully activity<br />
types associated with ice composition.JGR:120, 1859–1879. </ref> <br />
<ref> Raack, J.; et al. (2015). "Present-day seasonal gully activity in a south polar pit (Sisyphi Cavi) on Mars". Icarus. 251: 226–243. Bibcode:2015Icar..251..226R. doi:10.1016/j.icarus.2014.03.040. </ref> <br />
<ref> http://www.uahirise.org/ESP_044327_1375</ref> <br />
<ref> C. Pilorget, C., F. Forget. 2015. "CO2 Driven Formation of Gullies on Mars." 46th Lunar and Planetary Science Conference. 2471.pdf</ref> <br />
<ref> Pilorget, C.; Forget, F. (2016). "Formation of gullies on Mars by debris flows triggered by CO2 sublimation". Nature Geoscience. 9: 65–69. Bibcode:2016NatGe...9...65P. </ref> <br />
As the map below shows gullies and streaks are found in different areas on the planet.<br />
<gallery class="center" widths="190px" heights="180px"><br />
File:Streak Locations PIA09030.jpg|Map showing locations of gullies (brown) and streaks (pink)<br />
</gallery><br />
<br />
[[File:50858 1435gullies.jpg|600pxr|Image of gullies with main parts labeled. The main parts of a Martian gully are alcove, channel, and apron. Picture was taken by HiRISE under HiWish program.]]<br />
<br />
Like gullies and streaks, recurring slope lineae are seen on steep slopes, but they are smaller, more narrow, and straighter. Since they seem to lengthen as the temperature increases, they were believed to be involved with liquid water. <ref> McEwen, A. et al. 2011. Seasonal Flows on Warm Martian Slopes. Science, 333(6043), 740–743. doi:10.1126/science.1204816 PMID 21817049. http://www.sciencemag.org/content/333/6043/740. </ref> <br />
<ref> Mann, Adam (18 February 2014). "Strange Dark Streaks on Mars Get More and More Mysterious". Wired. Retrieved 18 February 2014. </ref> <br />
<ref> Chang, K. 2011. "Scientists Find Signs Water Is Flowing on Mars," New York Times, August 4, A13. https://www.nytimes.com/2011/08/05/science/space/05mars.html?_r=1&ref=marsplanet. </ref> <br />
<ref> HiRISE website. Seasonal Flows on Warm Martian Slopes. http://hirise.lpl.arizona.edu/sim/science-2011-aug-4.php. </ref> <br />
<ref> McEwen, A. Ojha L.; Dundas C.; Mattson, S.; Byrne S.; Wray J.; Cull S.; Murchie S. 2011. Transient Slope Lineae: Evidence for Summertime Briny Flows on Mars? 42nd Lunar and Planetary Science Conference, Abstract #2314. http://www.lpi.usra.edu/meetings/lpsc2011/pdf/2314.pdf. </ref> <br />
Nevertheless, later studies showed that very little water, if any, could be involved.<ref>Dundas, C., et al. 2017. Granular Flows at Recurring Slope Lineae on Mars Indicate a Limited Role for Liquid Water. Nature Geoscience. Nov. 20. [1].</ref> <ref>Schaefer, E., et al. 2018. A case study of recurring slope lineae (RSL) at Tivat crater: Implications for RSL origins. Icarus: In press. https://doi.org/10.1016/j.icarus.2018.07.014</ref><br />
<gallery class="center" widths="190px" heights="180px"><br />
File:Oblique View of Warm Season Flows in Newton Crater.jpg|Recurrent slop lineae, as seen by HiRISE<br />
</gallery><br />
<br />
== References ==<br />
{{reflist}}<br />
<br />
==See also==<br />
* [[Martian gullies]]<br />
* [[What Mars Actually Looks Like! ]] <br />
== External links ==<br />
* [[yt:_sUUKcZaTgA|Martian Ice - Jim Secosky - 16th Annual International Mars Society Convention]]</div>Akademyhttp://marspedia.org/index.php?title=Nuclear_power&diff=126242Nuclear power2018-09-23T16:16:41Z<p>Akademy: Improved.</p>
<hr />
<div>[[Image:nuclear_warning_sign.png|right|Nuclear Danger Icon]]<br />
<br />
'''Nuclear Power''' is a method of [[energy]] generation. It uses [[nuclear fuel]] to produce heat, which is usually transformed into [[electricity]]. Nuclear power is considered the preferred energy source for most plans for medium- to long-term human expeditions to [[Mars]].<br />
<br />
<br />
== Usage On Mars==<br />
The generation of electricity from nuclear fuel does not depend on [[environmental conditions|weather conditions]] so would be useful for maintaining a reliable source of power on Mars. However, due to the unclear availability of radioactive resources on Mars and the difficulty in preparing the fuel (the nuclear enrichment process) any nuclear fuel will have to be brought from [[Earth]] for the foreseeable future. This would significantly prevent the [[settlement]] from being [[independence from Earth|independent from Earth]].<br />
<br />
== Nuclear reactor ==<br />
In a nuclear reactor, heat caused by the radioactivity boils [[water]] to steam. [[turbine|Turbines]] are driven by the steam's pressure, spinning a dynamo to generate electric energy.<br />
<br />
== Nuclear heating ==<br />
Heating [[greenhouse]]s and other [[building]]s may be done indirectly by the heat of the nuclear fission. The heat can be transported in pipes from the reactor to the buildings. Heat exchangers avoid nuclear pollution of the buildings.<br />
<br />
== Types of Nuclear Generation ==<br />
<br />
=== RTG ===<br />
[[Radioisotope thermoelectric generator]]s (abbr.: RTG) are simple devices. They produce a heat difference, transformed by a [[thermocouple]] to electrical energy. The maintenance effort is low.<br />
However, RTGs do not provide enough power for a base.<br />
<br />
=== Nuclear Heatpipe Reactor ===<br />
Small to Medium [[Heatpipe Reactors]] offer stable, safe power that requires no outside support system or personnel and is immune to meltdown, it can be scaled from .5kw to 50mw for remote bases, small cities, and forward operating bases here on Earth, these reactors could power a Colony or a Spaceship for between 5 and 40 years with no maintenance, with no in-situ resources needed. <ref name=":0">Idaho National Labs, Dr. K.P Annath, Dr. Michael Kellar, Mr. James Werner, Dr James Sterbentz '' Portable Special Purpose Nuclear Reactor (2 MW) for Remote Operating Bases and Microgrids '', https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2017/power/Ananth19349.pdf, May 2017.</ref> <ref name=":1">NASA Kilopower Project, Dr. David Poston '' Small Nuclear Reactors for Mars - 21st Annual Mars Society Convention '', https://www.youtube.com/watch?v=NLE5YFuCmhw, Sep 2018.</ref><br />
<br />
== Open issues ==<br />
<br />
*What sort of nuclear fuel is needed?<br />
*How long can the described nuclear power stations work without replenishment of nuclear fuel?<br />
*What is known about nuclear resources on Mars?<br />
<br />
== References ==<br />
{{reflist}}<br />
<br />
== External links ==<br />
<br />
* None<br />
<br />
[[Category:Hi-tech]]<br />
[[Category:Energy]]</div>Akademyhttp://marspedia.org/index.php?title=User_talk:Akademy&diff=126241User talk:Akademy2018-09-23T16:15:17Z<p>Akademy: </p>
<hr />
<div>* Need template, of example of a good formatted page.<br />
** First paragraph should be a quick explanation, always in regards to Mars/The Mars Society. (For instance, the nuclear energy page explains what nuclear energy is, but also why it would be useful on Mars<br />
* "Coding standards" - e.g., title definitions should have spaces in: == title ==</div>Akademyhttp://marspedia.org/index.php?title=User_talk:Akademy&diff=126240User talk:Akademy2018-09-23T16:10:10Z<p>Akademy: Created page with "- Need template, of example of a good formatted page. - First paragraph should be a quick explanation, always in regards to Mars/The Mars Society. (For instance, the nuclear..."</p>
<hr />
<div>- Need template, of example of a good formatted page.<br />
- First paragraph should be a quick explanation, always in regards to Mars/The Mars Society. (For instance, the nuclear energy page explains what nuclear energy is, but also why it would be useful on Mars</div>Akademyhttp://marspedia.org/index.php?title=Nuclear_power&diff=126239Nuclear power2018-09-23T15:49:48Z<p>Akademy: Split up references.</p>
<hr />
<div>[[Image:nuclear_warning_sign.png|right|Nuclear Danger Icon]]<br />
<br />
'''Nuclear Power''' is a method of [[energy]] generation. It uses nuclear fuel to produce heat, which is usually transformed into [[electricity]].<br />
<br />
Nuclear power has been considered as the preferred energy source for most plans for medium- to long-term human expeditions to [[Mars]]. It does not depend on [[environmental conditions|weather conditions]].<br />
<br />
The availability of radioactive resources on Mars is unclear. Due to the vast effort of the nuclear enrichment process the nuclear fuel must be brought from [[Earth]], preventing the [[settlement]] from being [[independence from Earth|independent from Earth]].<br />
<br />
The maintenance effort of a legacy nuclear power station requires a huge staff. However, due to Russian plans to build a fully self-contained device on Mars the required maintenance staff comprises only 6 engineers.<br />
<br />
Heatpipe Reactors are self contained reactors that require no maintenance or maintenance personnel and can last from 5 to 40 years. <ref name=":0" /> <ref name=":1" /><br />
<br />
==RTG==<br />
[[Radioisotope thermoelectric generator]]s (abbr.: RTG) are simple devices. They produce a heat difference, transformed by a [[thermocouple]] to electrical energy. The maintenance effort is low.<br />
However, RTGs do not provide enough power for a base.<br />
<br />
==Nuclear reactor==<br />
In a nuclear reactor the heat boils [[water]] to steam. [[turbine|Turbines]] are driven by the steam's pressure, spinning a dynamo to generate electric energy.<br />
==Nuclear Heatpipe Reactor==<br />
Small to Medium Heatpipe Reactors offer stable safe Power that requires no outside support system or Personnel and is immune to meltdown, it can be scaled from .5kw to 50mw for remote bases, small cities, and forward operating bases here on Earth, these reactors could power a Colony or a Spaceship for between 5 and 40 years with no maintenance, with no in-situ resources needed. <ref name=":0">Idaho National Labs, Dr. K.P Annath, Dr. Michael Kellar, Mr. James Werner, Dr James Sterbentz '' Portable Special Purpose Nuclear Reactor (2 MW) for Remote Operating Bases and Microgrids '', https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2017/power/Ananth19349.pdf, May 2017.</ref> <ref name=":1">NASA Kilopower Project, Dr. David Poston '' Small Nuclear Reactors for Mars - 21st Annual Mars Society Convention '', https://www.youtube.com/watch?v=NLE5YFuCmhw, Sep 2018.</ref><br />
==Nuclear heating==<br />
Heating [[greenhouse]]s and other [[building]]s may be done indirectly by the heat of the nuclear fission. The heat can be transported in pipes from the reactor to the buildings. Heat exchangers avoid nuclear pollution of the buildings.<br />
<br />
==Open issues==<br />
<br />
*What sort of nuclear fuel is needed?<br />
*How long can the described nuclear power stations work without replenishment of nuclear fuel?<br />
*What is known about nuclear resources on Mars?<br />
<br />
== References ==<br />
{{reflist}}<br />
<br />
==External links==<br />
<br />
*[http://news.bbc.co.uk/2/hi/europe/3162129.stm BBC: Russia plans Mars nuclear station]<br />
<br />
[[Category:Hi-tech]]<br />
[[Category:Energy]]</div>Akademyhttp://marspedia.org/index.php?title=SpaceX&diff=126237SpaceX2018-09-23T15:35:23Z<p>Akademy: Set as stub</p>
<hr />
<div>{{Stub}}<br />
<br />
SpaceX is an US based company which builds and launches rockets into Space.<br />
<br />
The [[BFR]] is a one of the rockets SpaceX is in the process of designing. It is intended to launch large payloads into space which could reach the Moon, Mars and other celestial bodies.<br />
<br />
[https://www.spacex.com/ Official Website]</div>Akademyhttp://marspedia.org/index.php?title=SpaceX&diff=126236SpaceX2018-09-23T15:35:07Z<p>Akademy: Added official website link</p>
<hr />
<div>SpaceX is an US based company which builds and launches rockets into Space.<br />
<br />
The [[BFR]] is a one of the rockets SpaceX is in the process of designing. It is intended to launch large payloads into space which could reach the Moon, Mars and other celestial bodies.<br />
<br />
[https://www.spacex.com/ Official Website]</div>Akademyhttp://marspedia.org/index.php?title=SpaceX&diff=126235SpaceX2018-09-23T15:31:46Z<p>Akademy: Initial SpaceX page</p>
<hr />
<div>SpaceX is an US based company which builds and launches rockets into Space.<br />
<br />
The [[BFR]] is a one of the rockets SpaceX is in the process of designing. It is intended to launch large payloads into space which could reach the Moon, Mars and other celestial bodies.</div>Akademy