The Phoenix lander's 2008 Mars observations of droplets on its legs and evidence of atmospheric exchange with liquid water: Difference between revisions
The Phoenix lander's 2008 Mars observations of droplets on its legs and evidence of atmospheric exchange with liquid water (edit)
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Unfortunately, it wasn't equipped to analyse them but the leading theory is that these were droplets of salty water.<ref name=phoenix_droplets_2009/> They were observed to grow, darken and coalesce<ref>Staff writers, "The Salty Tears Of Phoenix Show Liquid Water On Mars", Mars Daily, Ann Arbor MI (SPX) Mar 19, 2009</ref>, and then disappear, presumably as a result of falling off the legs.
In December 2013, Nilton Renno<ref name="NiltonRennoFaculty">[http://clasp.engin.umich.edu/people/nrenno/FACULTY Nilton Renno - Faculty page], Mitchigen State University - Honors, Awards and Accomplishments, and Publications, etc</ref> and his team using the Michigan Mars Environmental Chamber were able to simulate the conditions at its landing site and the droplets<ref name="MicheganMars">https://www.researchgate.net/publication/283504377_The_Michigan_Mars_Environmental_Chamber_Preliminary_Results_and_Capabilities</ref>. They formed salty brines within minutes when salt overlaid ice, with the salt, especially perchlorates, acting as an "antifreeze"<ref name="GoughChevrier2014" />. The team concluded that suitable conditions for brine droplets may be widespread in the polar regions<ref name="salt_ice">[http://www.astrobio.net/news-brief/liquid-water-ice-salt-mars/ Liquid Water from Ice and Salt on Mars], Aaron L. Gronstal -Astrobiology Magazine (NASA), Jul 3, 2014</ref><ref name="salt_ice_paper">Fischer, E., Martínez, G.M., Elliott, H.M. and Rennó, N.O., 2014. [https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014GL060302 Experimental evidence for the formation of liquid saline water on Mars]. Geophysical research letters, 41(13), pp.4456-4462.</ref>. Nilton Renno talks about their results in this video
<youtube width="540" height="315">iLWv9UGwjdE</youtube>
The Phoenix droplets may have formed on mixtures of salt and ice that were thrown up onto its legs when it landed. <ref name=salt_ice/><ref name=salt_ice_paper/>. The Michegan Mars simulation chamber was developed to study the possibility of brines forming in Mars surface conditions:
{{quote|Introduction: We have developed the Michigan Mars Environmental Chamber (MMEC) to simulate the entire range of Martian surface and shallow subsurface conditions with respect to temperature, pressure, relative humidity, solar radiation and soil wetness. Our goal is to simulate the Martian diurnal cycle for equatorial as well as polar Martian conditions and test the hypothesis that salts known to exist in the Martian regolith can deliquesce and form brine pockets or layers by freeze-thaw cycles. Motivation: Liquid water is one of the necessary ingredients for the development of life as we know it. ... It has been shown that liquid brines are ubiquitous in the Martian polar regions and microbial communities have been seen to survive under similar conditions in Antarctica's Dry Valleys.|sign=|source=}}
===Phoenix isotope evidence of liquid water on the Mars surface in the recent geological past===
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