Viking 2 - Revision history

Suitupandshowup: /* Did we find life? */

2019-02-08T23:08:48Z

Did we find life?

Suitupandshowup: /* Life detection instruments */

2019-02-08T23:08:06Z

Life detection instruments

Suitupandshowup: /* Life detection instruments */

2019-02-08T23:07:08Z

Life detection instruments

Suitupandshowup: /* Life detection instruments */

2019-02-08T23:05:35Z

Life detection instruments

Suitupandshowup: /* Weather measurements */

2019-02-08T23:04:49Z

Weather measurements

Suitupandshowup: /* Weather measurements */

2019-02-08T23:03:10Z

Weather measurements

Suitupandshowup: /* What we learned about soil */

2019-02-08T23:01:59Z

What we learned about soil

Suitupandshowup at 22:58, 8 February 2019

2019-02-08T22:58:20Z

Suitupandshowup at 22:54, 8 February 2019

2019-02-08T22:54:25Z

Suitupandshowup at 22:53, 8 February 2019

2019-02-08T22:53:54Z

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 === Did we find life?===
-Three experiments on Viking looked life.  Although some activity was observed, most scientists now believe that the data were from inorganic chemical reactions of the soil.   A few scientists still to this day believe the results were due to living organisms.<ref> https://news.nationalgeographic.com/news/2012/04/120413-nasa-viking-program-mars-life-space-science/</ref> <ref>http://edition.cnn.com/2000/TECH/space/11/07/mars.sample/</ref>  <ref> https://www.youtube.com/watch?v=MX7vRut_lUg  </ref>  Because no organic chemicals were found in the soil, most scientists concluded there was no life detected at this location.   However, dry areas of Antarctica do not have detectable organic compounds either, but they have organisms living in the rocks.<ref>Friedmann, E.  1982.  Endolithic Microorganisms in the Antarctic Cold Desert.  Science: 215. 1045-1052.</ref>
+Three experiments on Viking looked life.  Although some activity was observed, most scientists now believe that the data were produces from inorganic chemical reactions of the soil.   A few scientists still to this day believe the results were due to living organisms.<ref> https://news.nationalgeographic.com/news/2012/04/120413-nasa-viking-program-mars-life-space-science/</ref> <ref>http://edition.cnn.com/2000/TECH/space/11/07/mars.sample/</ref>  <ref> https://www.youtube.com/watch?v=MX7vRut_lUg  </ref>  Because no organic chemicals were found in the soil, most scientists concluded there was no life detected at this location.   However, dry areas of Antarctica do not have detectable organic compounds either, but they have organisms living in the rocks.<ref>Friedmann, E.  1982.  Endolithic Microorganisms in the Antarctic Cold Desert.  Science: 215. 1045-1052.</ref>
 Early on, some suggested that the lack of a protective ozone layer would allow UV light to sterilize the soil surface.  Mars has almost no ozone layer, like the Earth, so UV light sterilizes the surface and may produce peroxides that would change any organic chemicals.<ref>Hartmann, W. 2003. A Traveler's Guide to Mars. Workman Publishing. NY NY.</ref>  These theories did seem to be valid as decades later the Phoenix Lander detected the chemical perchlorate in the Martian Soil. Perchlorate, a strong oxidant may have wipe out any traces of organic matter  in the Martian soil.<ref>[http://www.planetary.org/news/2008/0806_Alien_Rumors_Quelled_as_NASA_Announces.html Alien Rumors Quelled as NASA Announces Phoenix Perchlorate Discovery.] A.J.S. Rayl, August 6, 2008.</ref>  Carbon-based life would be difficult at the soil surface, if perchlorates were pervasive on Mars.   In addition, a study, published in the Journal of Geophysical Research in 2010, suggested  that organic compounds were actually present in the soil analyzed by both Viking 1 and 2. The study's authors found that perchlorate will destroy organics when heated and will produce chloromethane and dichloromethane, the same chlorine compounds discovered by both Viking landers when they performed the tests on Mars.<ref>Navarro-González, Rafael; et al. (2011). "Comment on "Reanalysis of the Viking results suggests perchlorate and organics at midlatitudes on Mars". Journal of Geophysical Research. 116 (E12): E12001.</ref> <ref>Navarro–Gonzáles, Rafael; Vargas, Edgar; de la Rosa, José; Raga, Alejandro C.; McKay, Christopher P. (2010-12-15). "Reanalysis of the Viking results suggests perchlorate and organics at midlatitudes on Mars". Journal of Geophysical Research: Planets. 115 (E12010): E12010.</ref>  <ref>Navarro-González, Rafael; Vargas, Edgar; de la Rosa, José; Raga, Alejandro C.; McKay, Christopher P. (2011). "Correction to "Reanalysis of the Viking results suggests perchlorate and organics at midlatitudes on Mars"". Journal of Geophysical Research. 116 (E8): E08011.</ref>  <ref>Navarro-González, Rafael; Navarro, Karina F.; de la Rosa, José; Iñiguez, Enrique; Molina, Paola; Miranda, Luis D.; Morales, Pedro; Cienfuegos, Edith; Coll, Patrice; et al. (2006). "The limitations on organic detection in Mars-like soils by thermal volatilization-gas chromatography-MS and their implications for the Viking results". Proceedings of the National Academy of Sciences. 103 (44): 16089–94.</ref>Since perchlorate would have broken down any Martian organics, there could be life at the Viking sites.<ref>https://www.sciencedaily.com/releases/2010/09/100904081050.htm</ref> <ref>https://web.archive.org/web/20140819090841/http://www.gillevin.com/Mars/Levin-Straat_Mars_Society_Paper_8-8-14.pdf</ref>

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 The gas exchange experiment examined gases given off by a soil sample after a liquid mixture of organic and inorganic chemicals were added.  Scientists expected that as any organisms consumed the nutrients, they would give off waste gases.<ref>Chambers, Paul (1999). Life on Mars; The Complete Story. London: Blandford. ISBN 978-0-7137-2747-0.</ref> The results were not consistent with life.
 In the  labeled release experiment very dilute aqueous nutrient solution that contained radioactive Carbon-14 were added to a sample.  If a type of animal ate some of the radioactive food, than it would breath out radioactive carbon dioxide.  We like all other animals eat food, use it for energy, and then breathe out carbon dioxide and water.  If our food contained radioactive carbon, then the carbon dioxide in our expelled air would also be radioactive.  Much to our surprise, this did happen.  When another sample was tested by first heating to destroy any microorganisms that might be present, no radioactive gas was given off.  Therefore, it seemed that the heating had indeed killed the life in the sample.  However, when additional nutrient fluid was put on a sample that had not been heated, the reaction did not give the same results.  In the end it, scientists said that the results were inconclusive.<ref>Levin, G. V.; Straat, P. A. (1976). "Viking Labeled Release Biology Experiment: Interim Results". Science. 194 (4271): 1322–1329.</ref> <ref>Levin, Gilbert V.; Straat, Patricia Ann (1979). "Completion of the Viking labeled release experiment on Mars". Journal of Molecular Evolution. 14 (1–3): 167–83.</ref>
-A third experiment, the pyrolytic release  experiment,  searched for organisms that carried out photosynthesis like plants on Earth.  In the experiment water, and gases (carbon monoxide and carbon dioxide) made radioactive were added to a soil sample and a light was turned on.   After several days, the gases were removed and the sample baked and examined to see if any of the gases were converted into organic compounds.  No radioactive compounds were found.  Apparently, there were not plant-like organisms changing simple compounds like water and carbon dioxide into organic chemicals.<ref>Kieffer, H., et al.  (eds)  1992.   Mars.   The University of Arizona Press.   Tucson</ref>
+A third experiment, the pyrolytic release  experiment,  searched for organisms that carried out photosynthesis like plants on Earth.  In the experiment water, and gases (carbon monoxide and carbon dioxide) made radioactive were added to a soil sample and a light was turned on.   After several days, the gases were removed and the sample baked and examined to see if any of the gases were converted into organic compounds.  No radioactive compounds were found.  Apparently, there were no plant-like organisms changing simple compounds like water and carbon dioxide into organic chemicals.<ref>Kieffer, H., et al.  (eds)  1992.   Mars.   The University of Arizona Press.   Tucson</ref>
 Besides carrying out experiments to look for organisms, Viking also looked for organic chemicals—the chemicals of all living things on Earth.   Both Viking landers used gas chromatograph — mass spectrometer to look for organic compounds.  Even though this instrument was capable of detecting organic molecules present at a level of a few parts/billion, none were found.

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 The gas exchange experiment examined gases given off by a soil sample after a liquid mixture of organic and inorganic chemicals were added.  Scientists expected that as any organisms consumed the nutrients, they would give off waste gases.<ref>Chambers, Paul (1999). Life on Mars; The Complete Story. London: Blandford. ISBN 978-0-7137-2747-0.</ref> The results were not consistent with life.
-In the  labeled release experiment very dilute aqueous nutrient solution that contained radioactive Carbon-14 were added to a sample.  If a type of animal ate some of the radioactive food, than it would breath out radioactive carbon dioxide.  We like all other animals eat food, use it for energy, and then breathe out carbon dioxide and water.  If our food contained radioactive carbon, then the carbon dioxide in our expelled air would also be radioactive.  Much to our surprise, this did happen.  When another sample was tested by first heating to destroy any microorganisms that might be present, no radioactive gas was given off.  Therefore, it seemed that the heating had indeed killed the life in the sample.  However, when additional nutrient fluid was put on a sample that had not been heated, the reaction did not give the same results.  In the end it, scientists saw the results were inconclusive.<ref>Levin, G. V.; Straat, P. A. (1976). "Viking Labeled Release Biology Experiment: Interim Results". Science. 194 (4271): 1322–1329.</ref> <ref>Levin, Gilbert V.; Straat, Patricia Ann (1979). "Completion of the Viking labeled release experiment on Mars". Journal of Molecular Evolution. 14 (1–3): 167–83.</ref>
+In the  labeled release experiment very dilute aqueous nutrient solution that contained radioactive Carbon-14 were added to a sample.  If a type of animal ate some of the radioactive food, than it would breath out radioactive carbon dioxide.  We like all other animals eat food, use it for energy, and then breathe out carbon dioxide and water.  If our food contained radioactive carbon, then the carbon dioxide in our expelled air would also be radioactive.  Much to our surprise, this did happen.  When another sample was tested by first heating to destroy any microorganisms that might be present, no radioactive gas was given off.  Therefore, it seemed that the heating had indeed killed the life in the sample.  However, when additional nutrient fluid was put on a sample that had not been heated, the reaction did not give the same results.  In the end it, scientists said that the results were inconclusive.<ref>Levin, G. V.; Straat, P. A. (1976). "Viking Labeled Release Biology Experiment: Interim Results". Science. 194 (4271): 1322–1329.</ref> <ref>Levin, Gilbert V.; Straat, Patricia Ann (1979). "Completion of the Viking labeled release experiment on Mars". Journal of Molecular Evolution. 14 (1–3): 167–83.</ref>
 A third experiment, the pyrolytic release  experiment,  searched for organisms that carried out photosynthesis like plants on Earth.  In the experiment water, and gases (carbon monoxide and carbon dioxide) made radioactive were added to a soil sample and a light was turned on.   After several days, the gases were removed and the sample baked and examined to see if any of the gases were converted into organic compounds.  No radioactive compounds were found.  Apparently, there were not plant-like organisms changing simple compounds like water and carbon dioxide into organic chemicals.<ref>Kieffer, H., et al.  (eds)  1992.   Mars.   The University of Arizona Press.   Tucson</ref>
 Besides carrying out experiments to look for organisms, Viking also looked for organic chemicals—the chemicals of all living things on Earth.   Both Viking landers used gas chromatograph — mass spectrometer to look for organic compounds.  Even though this instrument was capable of detecting organic molecules present at a level of a few parts/billion, none were found.

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 The gas exchange experiment examined gases given off by a soil sample after a liquid mixture of organic and inorganic chemicals were added.  Scientists expected that as any organisms consumed the nutrients, they would give off waste gases.<ref>Chambers, Paul (1999). Life on Mars; The Complete Story. London: Blandford. ISBN 978-0-7137-2747-0.</ref> The results were not consistent with life.
-In the  labeled release experiment very dilute aqueous nutrient solution that contained radioactive Carbon-14 were added to a sample.  If a type of animal ate some of the radioactive food, than it would breath out radioactive carbon.  We like all other animals eat food, use it for energy, and then breathe out carbon dioxide and water.  If our food contained radioactive carbon, then the carbon dioxide in our expelled air would also be radioactive.  Much to our surprise, this did happen.  When another sample was tested by first heating to destroy any microorganisms that might be present, no radioactive gas was given off.  Therefore, it seemed that the heating had indeed killed the life in the sample.  However, when additional nutrient fluid was put on a sample that had not been heated, the reaction did not give the same results.  In the end it, scientists saw the results were inconclusive.<ref>Levin, G. V.; Straat, P. A. (1976). "Viking Labeled Release Biology Experiment: Interim Results". Science. 194 (4271): 1322–1329.</ref> <ref>Levin, Gilbert V.; Straat, Patricia Ann (1979). "Completion of the Viking labeled release experiment on Mars". Journal of Molecular Evolution. 14 (1–3): 167–83.</ref>
+In the  labeled release experiment very dilute aqueous nutrient solution that contained radioactive Carbon-14 were added to a sample.  If a type of animal ate some of the radioactive food, than it would breath out radioactive carbon dioxide.  We like all other animals eat food, use it for energy, and then breathe out carbon dioxide and water.  If our food contained radioactive carbon, then the carbon dioxide in our expelled air would also be radioactive.  Much to our surprise, this did happen.  When another sample was tested by first heating to destroy any microorganisms that might be present, no radioactive gas was given off.  Therefore, it seemed that the heating had indeed killed the life in the sample.  However, when additional nutrient fluid was put on a sample that had not been heated, the reaction did not give the same results.  In the end it, scientists saw the results were inconclusive.<ref>Levin, G. V.; Straat, P. A. (1976). "Viking Labeled Release Biology Experiment: Interim Results". Science. 194 (4271): 1322–1329.</ref> <ref>Levin, Gilbert V.; Straat, Patricia Ann (1979). "Completion of the Viking labeled release experiment on Mars". Journal of Molecular Evolution. 14 (1–3): 167–83.</ref>
 A third experiment, the pyrolytic release  experiment,  searched for organisms that carried out photosynthesis like plants on Earth.  In the experiment water, and gases (carbon monoxide and carbon dioxide) made radioactive were added to a soil sample and a light was turned on.   After several days, the gases were removed and the sample baked and examined to see if any of the gases were converted into organic compounds.  No radioactive compounds were found.  Apparently, there were not plant-like organisms changing simple compounds like water and carbon dioxide into organic chemicals.<ref>Kieffer, H., et al.  (eds)  1992.   Mars.   The University of Arizona Press.   Tucson</ref>
 Besides carrying out experiments to look for organisms, Viking also looked for organic chemicals—the chemicals of all living things on Earth.   Both Viking landers used gas chromatograph — mass spectrometer to look for organic compounds.  Even though this instrument was capable of detecting organic molecules present at a level of a few parts/billion, none were found.

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 Viking 2 collected various weather data the whole time it was on the surface.  Temperatures at this location varied from a low of -189.4 degrees F (-123 C, 150 K) to a high of -9.4 degrees F (-23 C, 250 K).    As these temperatures were recorded in the far north, cold temperatures would be expected. Furthermore, pressure changes, seasonal dust storms, and transport of atmospheric gases between the polar caps were observed.<ref>https://nssdc.gsfc.nasa.gov/planetary/viking.html</ref>
-Together, the two Viking landers found that Mars undergoes extreme changes in pressure with changes in seasons.  In the first month on Mars, Viking measured a 5% drop in air pressure.  Much of the atmosphere freezes out onto one of the ice caps.  Carbon dioxide makes up 95% of the atmosphere.  Nitrogen was measured at 2-3 percent, argon was 1-2%, and only 0.1-0.44 was oxygen.  Vikings were even able to examine the ratio of isotopes in the gases in the atmosphere.  Nitrogen ratios lead scientists to believe that the atmosphere was once 4-5 times as dense as at present.  Over the years, the lighter isotopes of Nitrogen escaped the planet.<ref>French, B.  1977.  Mars:  The Viking Discoveries.  NASA.</ref>  This idea that the atmosphere was once much thicker has received support from later missions to study the atmosphere, especially from the MAVEN mission.<ref>B.M. Jakosky et al. 2017. Mars’ atmospheric history derived from upper-atmosphere measurements of 38Ar/36Ar. Science 355 (6332): 1408-1410; doi: 10.1126/science.aai7721</ref> <ref>https://www.nasa.gov/press-release/nasas-maven-reveals-most-of-mars-atmosphere-was-lost-to-space</ref>
+Together, the two Viking landers found that Mars undergoes extreme changes in pressure with changes in seasons.  In the first month on Mars, Viking measured a 5% drop in air pressure.  Much of the atmosphere freezes out onto one of the ice caps during the winter season.  Carbon dioxide makes up 95% of the atmosphere.  Nitrogen was measured at 2-3 percent, argon was 1-2%, and only 0.1-0.44 was oxygen.  Vikings were even able to examine the ratio of isotopes in the gases in the atmosphere.  Nitrogen ratios lead scientists to believe that the atmosphere was once 4-5 times as dense as at present.  Over the years, the lighter isotopes of Nitrogen escaped the planet.<ref>French, B.  1977.  Mars:  The Viking Discoveries.  NASA.</ref>  This idea that the atmosphere was once much thicker has received support from later missions to study the atmosphere, especially from the MAVEN mission.<ref>B.M. Jakosky et al. 2017. Mars’ atmospheric history derived from upper-atmosphere measurements of 38Ar/36Ar. Science 355 (6332): 1408-1410; doi: 10.1126/science.aai7721</ref> <ref>https://www.nasa.gov/press-release/nasas-maven-reveals-most-of-mars-atmosphere-was-lost-to-space</ref>
 ==Life detection instruments==

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 ==Weather measurements==
-Viking 2 collected various weather data the whole time it was on the surface.  Temperatures at this location varied from a low of -189.4 degrees F (-123 C, 150 K) to a high of -9.4 degrees F (-23 C, 250 K).    As these temperatures were recorded in the far north, cold temperatures would be expected. Furthermore, pressure change , seasonal dust storms, and transport of atmospheric gases between the polar caps were observed.<ref>https://nssdc.gsfc.nasa.gov/planetary/viking.html</ref>
+Viking 2 collected various weather data the whole time it was on the surface.  Temperatures at this location varied from a low of -189.4 degrees F (-123 C, 150 K) to a high of -9.4 degrees F (-23 C, 250 K).    As these temperatures were recorded in the far north, cold temperatures would be expected. Furthermore, pressure changes, seasonal dust storms, and transport of atmospheric gases between the polar caps were observed.<ref>https://nssdc.gsfc.nasa.gov/planetary/viking.html</ref>
 Together, the two Viking landers found that Mars undergoes extreme changes in pressure with changes in seasons.  In the first month on Mars, Viking measured a 5% drop in air pressure.  Much of the atmosphere freezes out onto one of the ice caps.  Carbon dioxide makes up 95% of the atmosphere.  Nitrogen was measured at 2-3 percent, argon was 1-2%, and only 0.1-0.44 was oxygen.  Vikings were even able to examine the ratio of isotopes in the gases in the atmosphere.  Nitrogen ratios lead scientists to believe that the atmosphere was once 4-5 times as dense as at present.  Over the years, the lighter isotopes of Nitrogen escaped the planet.<ref>French, B.  1977.  Mars:  The Viking Discoveries.  NASA.</ref>  This idea that the atmosphere was once much thicker has received support from later missions to study the atmosphere, especially from the MAVEN mission.<ref>B.M. Jakosky et al. 2017. Mars’ atmospheric history derived from upper-atmosphere measurements of 38Ar/36Ar. Science 355 (6332): 1408-1410; doi: 10.1126/science.aai7721</ref> <ref>https://www.nasa.gov/press-release/nasas-maven-reveals-most-of-mars-atmosphere-was-lost-to-space</ref>

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 Results from Viking soil sample analysis are consistent with what other landers have discovered.  Both Spirit Rover and the Opportunity Rover found sulfates on Mars.<ref>http://marsrovers.nasa.gov/gallery/press/opportunity/20040625a.html</ref>  The Opportunity Rover (landed in 2004 with advanced instruments) found magnesium sulfate and calcium sulfate at Meridiani Planum.<ref>Christensen, P. et al.  2004.  Mineralogy at Meridiani Planum from the Mini-TES Experiment on the Opportunity Rover.  Science: 306. 1733-1739</ref>
 Mineral models suggest that the soil could be a mixture of about 90% iron-rich clay, about 10% magnesium sulfate (kieserite?), about 5% carbonate (calcite), and about 5% iron oxides (hematite, magnetite, goethite?).  These minerals are typical weathering products of mafic igneous rocks.  The dark, igneous rock basalt is believed to make up much of the surface of Mars, as it does for the Earth.<ref>Baird, A.  et al.  1976.  Mineralogic and Petrologic Implications of Viking Geochemical Results From Mars: Interim Report.  Science: 194. 1288-1293.</ref> <ref>Toulmin III, P. et al.  1977.  Geochemical and Mineralogical Interpretation of the Viking Inorganic Chemical Results.  Journal of Geophysical Research: 82. 4625-4634.</ref> <ref>Clark, B. et al.  1982.  Chemical Composition of Martian Fines.  Journal of Geophysical Research: 87. 10059-10097</ref>
 Scientists have tried repeatedly  to determine the nature of the magnetic component in Martian dust.  Studies with magnets aboard the Viking  landers indicated that the soil is between 3 and 7 percent magnetic materials by weight.  The magnetic chemicals could be magnetite and maghemite.  These could come from the weathering of basalt rock.<ref>Hargraves, R. et al. 1976.  Viking Magnetic Properties Investigation: Further Results.  Science: 194.  1303-1309.</ref> <ref>Arvidson, R, A. Binder, and K. Jones.  The Surface of Mars.  Scientific American</ref>
-The Pathfinder mission carried several magnets of varying strength.   Because  the weakest magnet did not attract any soil, researchers concluded that the dust did not contain pure magnetite or just one type of maghemite. Rather, they thought Mars dust probably was an aggregate possibly cemented with[ferric oxide (Fe<sub>2</sub>O<sub>3</sub>).<ref>Hviid, S.  et al.  1997.  "Magnetic Properties Experiments on the Mars Pathfinder Lander:  Preliminary Results".  ''Science'':278.  1768–1770.</ref>
+The Pathfinder mission carried several magnets of varying strength.   Because  the weakest magnet did not attract any soil, researchers concluded that the dust did not contain pure magnetite or just one type of maghemite. Rather, they thought Mars dust probably was an aggregate possibly cemented withferric oxide (Fe<sub>2</sub>O<sub>3</sub>).<ref>Hviid, S.  et al.  1997.  "Magnetic Properties Experiments on the Mars Pathfinder Lander:  Preliminary Results".  ''Science'':278.  1768–1770.</ref>
 Experiments carried out by the Mars Spirit Rover (landed in 2004) indicated that magnetite could explain the magnetic nature of the dust and soil on Mars.  Magnetite was found in the soil and that the most magnetic part of the soil was dark.  Magnetite is very dark.<ref>Bertelsen, P. et al.  2004.  Magnetic Properties Experiments on the Mars Exploration rover Spirit at Gusev Crater.  Science: 305. 827-829.</ref>

← Older revision		Revision as of 22:58, 8 February 2019
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−	Viking 2, was launched on September 9, 1975, using a Titan III rocket with Centaur (rocket stage) upper stages. It entered orbit on August 7, 1975. After studying Mars from orbit for over a month, scientists sent the lander to the surface. Its exact landing site was about 200 km west of Mie Crater in Utopia Planitia in the Cebrenia quadrangle at 47.64 degrees N and 134.29 degrees E.<ref> https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1975-083C</ref> The location can easily be seen on maps of Mars because Mie Crater sits by itself in the north. For over four years it imaged the surface, analyzed soil samples, and performed experiments that looked for life. The last message from Viking Lander 2 came to Earth on April 11,1980.<ref> https://www.jpl.nasa.gov/news/fact_sheets/viking.pdf</ref> The last communication with the Viking 2 Orbiter occurred on July 25, 1978.<ref>Kieffer, H., et al. (eds) 1992. Mars. The University of Arizona Press. Tucson</ref> By the end of the Orbiter’s mission, it had returned nearly 16,000 images in its 706 orbits around the Red Planet.<ref>https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1975-083A</ref>	+	Viking 2, was launched on September 9, 1975, using a Titan III rocket with Centaur (rocket stage) upper stages. It entered orbit on August 7, 1975. After studying Mars from orbit for over a month, scientists sent the lander to the surface. Its exact landing site was about 200 km west of Mie Crater in Utopia Planitia in the Cebrenia quadrangle at 47.64 degrees N and 134.29 degrees E (225.71 W).<ref> https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1975-083C</ref> The location can easily be seen on maps of Mars because Mie Crater sits by itself in the north. For over four years it imaged the surface, analyzed soil samples, and performed experiments that looked for life. The last message from Viking Lander 2 came to Earth on April 11,1980.<ref> https://www.jpl.nasa.gov/news/fact_sheets/viking.pdf</ref> The last communication with the Viking 2 Orbiter occurred on July 25, 1978.<ref>Kieffer, H., et al. (eds) 1992. Mars. The University of Arizona Press. Tucson</ref> By the end of the Orbiter’s mission, it had returned nearly 16,000 images in its 706 orbits around the Red Planet.<ref>https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1975-083A</ref>

	[[File:Vikinglander2-1viking2.jpg\|600pxr\|View of surface around Viking 2]]		[[File:Vikinglander2-1viking2.jpg\|600pxr\|View of surface around Viking 2]]

← Older revision		Revision as of 22:54, 8 February 2019
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−	Viking 2, was launched on September 9, 1975, using a Titan III rocket with Centaur (rocket stage) upper stages. It entered orbit on August 7, ~~1875~~. After studying Mars from orbit for over a month, scientists sent the lander to the surface. Its exact landing site was about 200 km west of Mie Crater in Utopia Planitia in the Cebrenia quadrangle at 47.64 degrees N and 134.29 degrees E.<ref> https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1975-083C</ref> The location can easily be seen on maps of Mars because Mie Crater sits by itself in the north. For over four years it imaged the surface, analyzed soil samples, and performed experiments that looked for life. The last message from Viking Lander 2 came to Earth on April 11,1980.<ref> https://www.jpl.nasa.gov/news/fact_sheets/viking.pdf</ref> The last communication with the Viking 2 Orbiter occurred on July 25, 1978.<ref>Kieffer, H., et al. (eds) 1992. Mars. The University of Arizona Press. Tucson</ref> By the end of the Orbiter’s mission, it had returned nearly 16,000 images in its 706 orbits around the Red Planet.<ref>https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1975-083A</ref>	+	Viking 2, was launched on September 9, 1975, using a Titan III rocket with Centaur (rocket stage) upper stages. It entered orbit on August 7, 1975. After studying Mars from orbit for over a month, scientists sent the lander to the surface. Its exact landing site was about 200 km west of Mie Crater in Utopia Planitia in the Cebrenia quadrangle at 47.64 degrees N and 134.29 degrees E.<ref> https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1975-083C</ref> The location can easily be seen on maps of Mars because Mie Crater sits by itself in the north. For over four years it imaged the surface, analyzed soil samples, and performed experiments that looked for life. The last message from Viking Lander 2 came to Earth on April 11,1980.<ref> https://www.jpl.nasa.gov/news/fact_sheets/viking.pdf</ref> The last communication with the Viking 2 Orbiter occurred on July 25, 1978.<ref>Kieffer, H., et al. (eds) 1992. Mars. The University of Arizona Press. Tucson</ref> By the end of the Orbiter’s mission, it had returned nearly 16,000 images in its 706 orbits around the Red Planet.<ref>https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1975-083A</ref>

	[[File:Vikinglander2-1viking2.jpg\|600pxr\|View of surface around Viking 2]]		[[File:Vikinglander2-1viking2.jpg\|600pxr\|View of surface around Viking 2]]

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 Viking 2 was one of the two spacecraft of the Viking program that studied Mars both from orbit and from the surface. <ref>https://nssdc.gsfc.nasa.gov/planetary/viking.html</ref>
-Each of the Viking craft had two main parts.  The orbiters photographed  nearly the entire surface of Mars while the lander performed many experiments on the ground.  The orbiters also relayed data from the landers to the Earth after they touched down.<ref> https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1975-083A</ref>
+Each of the Viking craft had two main parts.  The orbiters photographed  nearly the entire surface of Mars, while the lander performed many experiments on the ground.  The orbiters also relayed data from the landers to the Earth after they touched down.<ref> https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1975-083A</ref>
 [[File:Viking orbiter.jpg |600pxr| Viking as it traveled to Mars with orbiter at the top and lander at the bottom]]