Water - Revision history

Suitupshowup at 16:10, 17 January 2026

2026-01-17T16:10:37Z

Suitupshowup: /* Current liquid water */

2026-01-17T16:08:25Z

Current liquid water

Suitupshowup: /* Current liquid water */ added new info and ref about effects of ice cover

2026-01-17T16:07:06Z

Current liquid water: added new info and ref about effects of ice cover

RichardWSmith: /* Climate change and polar obliquity */ max angle is 60 degrees not 90.

2024-10-17T23:08:44Z

Climate change and polar obliquity: max angle is 60 degrees not 90.

RichardWSmith: /* Climate change and polar obliquity */ Added link.

2024-09-15T10:07:56Z

Climate change and polar obliquity: Added link.

RichardWSmith: New section on climate change & polar obliquity.

2024-09-15T10:04:43Z

New section on climate change & polar obliquity.

Suitupandshowup: /* External links */ added to list

2023-03-20T23:26:13Z

External links: added to list

Michel Lamontagne: /* Industrial processes */

2023-03-15T00:39:20Z

Industrial processes

Michel Lamontagne: /* Current water ice */

2023-02-13T19:38:59Z

Current water ice

Kee.nethery: /* Regolith */

2021-11-15T01:56:11Z

Regolith

@@ Line 49: / Line 49: @@
 [[Image:Water_deposit.jpg|thumb|left|200px|Evidence from the [[Mars Global Surveyor]] MOC instrument that spurts of liquid water may sporadically flow on the Martian surface]]
 However, surface water on Mars is short-lived. The Martian atmosphere is very thin (a pressure of 7 millibars, <1% that of Earth's thick atmosphere) and cold (an average global temperature of -55°C or -67F), these two factors deny any long-term existence of liquid water. Surface liquid water will quickly freeze and [[sublimation|sublime]] into the atmosphere, bypassing the [[triple point|liquid phase]].  A large group of researchers modeled the effects of ice cover on a lake in Gale Crater.  They found that
-Liquid water can remain in a lake for 100–125 years when the climate is cold (seasonally below 0°C), humid (70%), and gets ∼50–100 mm of water every month.  The greater the concentration of salts, the more the freezing point is depressed.  As a result the thickness of the ice and the amount of ice cover is lower than with pure water.
+liquid water can remain in a lake for 100–125 years when the climate is cold (seasonally below 0°C), humid (70%), and gets ∼50–100 mm of water every month.  The greater the concentration of salts, the more the freezing point is depressed.  As a result the thickness of the ice and the amount of ice cover is lower than with pure water.
- Ice contributes to lake durability by minimizing evaporation rates during times of partial or total ice cover.<ref>Moreland, E., et al.  2026.  Seasonal Ice Cover Could Allow Liquid Lakes to Persist in a Cold Mars Paleoclimate. AGU Advances.  e2025AV001891</ref>
+Ice contributes to lake durability by minimizing evaporation rates during times of partial or total ice cover.<ref>Moreland, E., et al.  2026.  Seasonal Ice Cover Could Allow Liquid Lakes to Persist in a Cold Mars Paleoclimate. AGU Advances.  e2025AV001891</ref>
 This phase transition for water on Mars is much like the phase transition for liquid carbon dioxide on Earth when it is released from a CO<sub>2</sub> fire extinguisher to produce dry ice snow and CO<sub>2</sub> gas. The phase transition for H<sub>2</sub>O on the surface of Mars occurs below the "[[triple point]]" on the phase diagram so the recent observations of sediment on the surface will have been deposited very quickly by short lived "spurts" of water. Just how short-lived these spurts of water are it is unknown, but a significant volume must have created a formidable river to carry sediment several hundred meters.

@@ Line 49: / Line 49: @@
 [[Image:Water_deposit.jpg|thumb|left|200px|Evidence from the [[Mars Global Surveyor]] MOC instrument that spurts of liquid water may sporadically flow on the Martian surface]]
 However, surface water on Mars is short-lived. The Martian atmosphere is very thin (a pressure of 7 millibars, <1% that of Earth's thick atmosphere) and cold (an average global temperature of -55°C or -67F), these two factors deny any long-term existence of liquid water. Surface liquid water will quickly freeze and [[sublimation|sublime]] into the atmosphere, bypassing the [[triple point|liquid phase]].  A large group of researchers modeled the effects of ice cover on a lake in Gale Crater.  They found that
- Liquid water can remain in a lake for 100–125 years when the climate is cold (seasonally below 0°C), humid (70%), and gets ∼50–100 mm of water every month.  The greater the concentration of salts, the more the freezing point is depressed.  As a result the thickness of the ice and the amount of ice cover is lower than with pure water.
+Liquid water can remain in a lake for 100–125 years when the climate is cold (seasonally below 0°C), humid (70%), and gets ∼50–100 mm of water every month.  The greater the concentration of salts, the more the freezing point is depressed.  As a result the thickness of the ice and the amount of ice cover is lower than with pure water.
   Ice contributes to lake durability by minimizing evaporation rates during times of partial or total ice cover.<ref>Moreland, E., et al.  2026.  Seasonal Ice Cover Could Allow Liquid Lakes to Persist in a Cold Mars Paleoclimate. AGU Advances.  e2025AV001891</ref>

@@ Line 48: / Line 48: @@
 The [[Mars Global Surveyor]] arrived at the Red Planet on September 11, 1997 and returned a decade of data on the evolution of the planet before it was lost in November 2006 through energy loss. It was Mars' longest operational artificial satellite. The Mars Orbiter Camera (MOC) onboard revealed new deposits possibly carried as sediment by flowing water in two locations in the past 7 years (press release dated December 6, 2006)<ref>[http://mars.jpl.nasa.gov/mgs/newsroom/20061206a.html NASA Press Release: ''NASA Images Suggest Water Still Flows in Brief Spurts on Mars'']</ref>. In images taken in August 1999 and September 2006 of the same location ([[Centauri Montes]] Region), a bright deposit measuring several hundred meters long is evident in the 2006 image but not in the 1999 image. A similar feature was observed at a different location from 2001 to 2005 at [[Terra Sirenum]]. It is worth noting that both locations are in equatorial regions, not usually associated with ice or liquid water. This suggests liquid water remains a characteristic of the Mars landscape, if only sporadically. These discoveries have increased the enthusiasm for the search for [[microbes|microbial life]], but the implications for manned exploration are huge. If there are pockets of liquid water just below the surface, Mars may yet be able to provide our future pioneers with natural springs more familiar on Earth.
 [[Image:Water_deposit.jpg|thumb|left|200px|Evidence from the [[Mars Global Surveyor]] MOC instrument that spurts of liquid water may sporadically flow on the Martian surface]]
-However, surface water on Mars is short-lived. The Martian atmosphere is very thin (a pressure of 7 millibars, <1% that of Earth's thick atmosphere) and cold (an average global temperature of -55°C or -67F), these two factors deny any long-term existence of liquid water. Surface liquid water will quickly freeze and [[sublimation|sublime]] into the atmosphere, bypassing the [[triple point|liquid phase]].  This phase transition for water on Mars is much like the phase transition for liquid carbon dioxide on Earth when it is released from a CO<sub>2</sub> fire extinguisher to produce dry ice snow and CO<sub>2</sub> gas. The phase transition for H<sub>2</sub>O on the surface of Mars occurs below the "[[triple point]]" on the phase diagram so the recent observations of sediment on the surface will have been deposited very quickly by short lived "spurts" of water. Just how short-lived these spurts of water are it is unknown, but a significant volume must have created a formidable river to carry sediment several hundred meters.
+However, surface water on Mars is short-lived. The Martian atmosphere is very thin (a pressure of 7 millibars, <1% that of Earth's thick atmosphere) and cold (an average global temperature of -55°C or -67F), these two factors deny any long-term existence of liquid water. Surface liquid water will quickly freeze and [[sublimation|sublime]] into the atmosphere, bypassing the [[triple point|liquid phase]].  A large group of researchers modeled the effects of ice cover on a lake in Gale Crater.  They found that
 At times, the humidity of the Martian atmosphere can reach 100% (at Mars' temperature and pressure).  If the temperature was high, salty brines could last several minutes on the Martian surface.

@@ Line 55: / Line 55: @@
 ===Climate change and polar obliquity===
-Earth axis is 23 degrees from its orbital plane, and it does not vary much from this value due to our large moon.  However, planets with no large moon, can have the axis shift far more from gravitation interactions from other planets (especially Jupiter).  Mars has no large moon, and is closer to Jupiter, so it slowly cycles between the pole being almost 90 degrees from its orbital plane, and times when its axis being closer to being on the orbital plane.  In other words, sometimes Mars is tilted more to its side. <ref>https://www.spacedaily.com/news/mars-water-science-00d.html#:~:text=As%20I%20said%20in%20my,tuggings%20of%20our%20large%20Moon).</ref>
+Earth axis is 23 degrees from its orbital plane, and it does not vary much from this value due to our large moon.  However, planets with no large moon, can have the axis shift far more from gravitation interactions from other planets (especially Jupiter).  Mars has no large moon, and is closer to Jupiter, so it slowly cycles between the pole being almost 60 degrees from its orbital plane, and times when its axis being closer to being on the orbital plane.  In other words, sometimes Mars is tilted more to its side. <ref>https://www.spacedaily.com/news/mars-water-science-00d.html#:~:text=As%20I%20said%20in%20my,tuggings%20of%20our%20large%20Moon).</ref>
 Mars poles vary from 15 degrees to 35 degrees, in a 124,000 year cycle.  Mars is currently tilted 25 degrees.  Some scientists suggest that in the past, Mars' axil tilt varied between 0 degrees to 60 degrees, tens of millions of years ago.

← Older revision		Revision as of 10:07, 15 September 2024
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	This article has a nice illustration of this idea: <ref>https://www.jpl.nasa.gov/images/pia11714-mars-obliquity-cycle-illustration \| Mars Obliquity Cycle Illustration. </ref>		This article has a nice illustration of this idea: <ref>https://www.jpl.nasa.gov/images/pia11714-mars-obliquity-cycle-illustration \| Mars Obliquity Cycle Illustration. </ref>
		+
		+	This page: [[Periodic climate changes on Mars]] discusses this more, and has many photographs of land forms that may have been created from these cycles.

	==Water production==		==Water production==

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 At times, the humidity of the Martian atmosphere can reach 100% (at Mars' temperature and pressure).  If the temperature was high, salty brines could last several minutes on the Martian surface.
 Although there may be other explanations for these long "channels" of sediment, such as rock slides or wind-blown [[sand]] features, the appearance of the deposits seem very water-like. Michael Malin of Malin Space Science Systems, a mission scientist for the MOC says, "''The shapes of these deposits are what you would expect to see if the material were carried by flowing water... they have finger-like branches at the downhill end and easily diverted around small obstacles''".<ref>[http://mars.jpl.nasa.gov/mgs/newsroom/20061206a.html NASA Press Release: ''NASA Images Suggest Water Still Flows in Brief Spurts on Mars'']</ref>  It is also possible that other liquids such as 1,2-butanediol, 1,3-butanediol, 1,2-propanediol, 1,3-propanediol,  ethylene glycol and related liquids could be responsible for [[Recent Liquid Flow on Mars|fluid flow features]] on Mars.  While such liquids would be relatively more rare than water, the resistance to freezing of such liquids and mixtures of such liquids with water would allow them to cause fluid flow effects where pure liquid water is impossible.
 ==Water production==

← Older revision		Revision as of 23:26, 20 March 2023
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	==External links==		==External links==
		+
		+	*Head, J., et al. 2023. GEOLOGICAL AND CLIMATE HISTORY OF MARS: IDENTIFICATION OF POTENTIAL WARM AND
		+	WET CLIMATE ‘FALSE POSITIVES’. 54th Lunar and Planetary Science Conference 2023 (LPI Contrib. No. 2806). 1731.pdf

	*[https://www.youtube.com/watch?v=m2ERsEXAq_s Jeffrey Plaut - Subsurface Ice - 21st Annual International Mars Society Convention]		*[https://www.youtube.com/watch?v=m2ERsEXAq_s Jeffrey Plaut - Subsurface Ice - 21st Annual International Mars Society Convention]

@@ Line 95: / Line 95: @@
 Power sources which rely on heat engines (such as [[nuclear power]]) require a heat sink to provide the heat differential required for the engine to run. Water or Ice make good materials for this heat sink as they are dense and have high thermal mass. The ice of [[korolev|Korolev Crater]] has been suggested as a potential heat sink sufficient to provide for colony scale power generation.
-[[Deuterium]] from martian water may provide a source of fusion fuel for future energy production. Note that deuterium is 2.5 times more concentrated on Mars than on Earth, and may form a viable export.
+[[Deuterium]] from martian water may provide a source of fusion fuel for future energy production. Note that deuterium is about six times more concentrated on Mars than on Earth, and may form a viable export.
 [[Methanol]] and [[methane]] may be used to feed [[Biological_reactors|methanotrophs]] to produce food or other biologically produced industrial materials.

@@ Line 27: / Line 27: @@
 ===Current water ice===
-Today, water on Mars appears to be concentrated in Martian polar ice, suggesting Mars may once have had a warmer climate, slowly cooling as the atmosphere became a more inefficient insulator for the meager heating from the distant Sun.
+Today, water on Mars appears to be concentrated in Martian polar ice, suggesting Mars may once have had a warmer climate, slowly cooling as the atmosphere became a more inefficient insulator for the meager heating from the distant Sun.  There appears to be very large amounts of water frozen into the regolith just bellow the surface.  These areas may exist even at the Martian Equator.
 In 2004 the [[Mars Express]] orbiter detected spectral evidence of water in the south pole's ice cap and the surrounding area, which ruled out the possibility that the southern ice cap consisted of only carbon dioxide ice.<ref>European Space Agency. March 17, 2004. Water at Martian south pole. https://www.esa.int/Science_Exploration/Space_Science/Mars_Express/Water_at_Martian_south_pole</ref>
@@ Line 40: / Line 40: @@
 ====Abundance====
 [[Image:MARSIS.jpg|thumb|200px|right|A MARSIS map of Mars' south pole ice deposits.]]
 On March 15, 2007, [[Mars Express]]' mission control released more news of extensive frozen water discovered at the Martian [[south pole]]. These new and highly accurate measurements predict that if the ice were to be melted, the whole planet would be covered in a liquid layer 11 meters deep.<ref>The European Space Agency. September 1 2019. Mars Express science highlights: #4. Probing the polar regions. <nowiki>https://sci.esa.int/web/mars-express/-/51824-4-probing-the-polar-regions</nowiki></ref> Although it has been known for many years that the poles have an abundance of ice, it has never been measured to this degree of accuracy. The data comes from the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) currently mapping the north pole to gain a better understanding of how much frozen water may be contained there. MARSIS can probe over 2 miles below the Martian surface and has found extensive layered deposits of ice.
 ===Current liquid water===

@@ Line 73: / Line 73: @@
 One way to obtain water from regolith is to cover a spot with a clear cover, heat it with focused sunlight (mirrors), and let the water vapor condense on the cover. Collect the condensate on the edges of the cover. At ground level the Martian atmosphere has a pressure of 6.518 millibars or 0.095 psi as compared to the Earth's sea level atmospheric pressure of 14.7 psi. <ref>Mars. Mars.nasa.gov. (1997). Retrieved 15 November 2021, from https://mars.nasa.gov/MPF/mpf/realtime/mars2.html.</ref> Boiling point of water at 6.518 millibars: 1.5 degC, 34.7 degF. <ref>Water - Boiling Points at Vacuum Pressure. Engineeringtoolbox.com. (2021). Retrieved 15 November 2021, from https://www.engineeringtoolbox.com/water-evacuation-pressure-temperature-d_1686.html.</ref>
-"Excavated regolith can be processed by crushing, dry-grinding, and running it through a continuous feed electrically heated rotary kiln, heating to temperatures above 500˚C to decompose perchlorates, <ref>James D. Little (2019). 3: Aeneas Complex: A Plan For A Sustainable, Permanent 1000 Person Settlement On Mars in the book Mars colonies: Plans for Settling the Red Planet (p. 58).</ref><ref>Marvin, G., Woolaver, L., Thermal Decomposition of Perchlorates, Industrial & Engineering Chemistry Analytical Edition, 1945, Vol. 17, Iss. 8, pp. 474-476.</ref><ref>Bruck. A., Sutter, B., Ming, D., Mahaffy, P., Thermal Decomposition of Calcium Perchlorate/Iron-mineral Mixtures: Implications of the Evolved Oxygen from the Rocknest Eolian Deposit in Gale Crater, Mars., 45th Lunar and Planetary Science Conference, Mar. 2014.</ref>
+"Excavated regolith can be processed by crushing, dry-grinding, and running it through a continuous feed electrically heated rotary kiln, heating to temperatures above 500˚C to decompose perchlorates, <ref>James D. Little (2019). 3: Aeneas Complex: A Plan For A Sustainable, Permanent 1000 Person Settlement On Mars in the book Mars colonies: Plans for Settling the Red Planet (p. 58).</ref><ref>Marvin, G., Woolaver, L., Thermal Decomposition of Perchlorates, Industrial & Engineering Chemistry Analytical Edition, 1945, Vol. 17, Iss. 8, pp. 474-476.</ref><ref>Bruck. A., Sutter, B., Ming, D., Mahaffy, P., Thermal Decomposition of Calcium Perchlorate/Iron-mineral Mixtures: Implications of the Evolved Oxygen from the Rocknest Eolian Deposit in Gale Crater, Mars., 45th Lunar and Planetary Science Conference, Mar. 2014.</ref> <br>
-[Ca(H<sub>2</sub>O)<sub>4</sub>](ClO<sub>4</sub>)<sub>2</sub> -> Ca(ClO<sub>4</sub>)<sub>2</sub> + 4H<sub>2</sub>O
+[Ca(H<sub>2</sub>O)<sub>4</sub>](ClO<sub>4</sub>)<sub>2</sub> -> Ca(ClO<sub>4</sub>)<sub>2</sub> + 4H<sub>2</sub>O<br>
 oxides, sulfates, carbonates, and nitrates driving off gases and water vapor. The gases are processed through aseries of PSA equipment. The remaining regolith can be sifted and sorted, using various ore processing techniques, such as magnetic separation for iron rich minerals, and sifting to produce aggregate mixtures suitable for producing 3D printed sulfur concrete."