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Written by spacetravel.org
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Sunday, 03 July 2005 22:15 |
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The French-built spectrometer OMEGA, aboard the European Space Agencys Mars Express orbiter, has revealed that Mars is coated with hydrated silicates and sulfate salts. These deposits were probably left behind when standing water or ice dried up eons ago.
OMEGA has detected gypsum, which forms in the presence of water, calcium and sulfur. Gypsum on Mars was probably created by volcanic materials interacting with ground water. It has detected hematite, which was also seen by the Mars rover Opportunity and the Mars Global Surveyor, jarosite, a potassium-rich sulfate mineral, and kieserite, a magnesium-sulfate mineral. The deposits have been found all over the planet, in the polar regions, in broad areas near Syrtis Major and in layered deposits around Valles Marineris, indicating that, in the past, Mars might have had water all over it surface.
OMEGA principal investigator Jean-Pierre Bibring of the Space Astrophysics Institute in France warns, however, that we cannot assume that the sulfates that were found on Mars are exactly like evaporites on Earth. They might come from acid rain from volcanic outgassing, rather than from the evaporation of water.
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