Clays and sulfates suggest standing bodies of water on early Mars.
Mars Express evidence for large aquifers on early Mars
30 November 2005
Substantial quantities of liquid water must have been stably present in the early history of Mars. The findings of OMEGA, on board ESA's Mars Express, have implications on the climatic history of the planet and the question of its 'habitability' at some point in its history.
<a href="http://www.esa.int/SPECIALS/Results_from_Mars_Express_and_Huygens/SEMA1UULWFE_0.html>http://www.esa.int/SPECIALS/Results_from_Mars_Express_and_Huygens/SEMA1UULWFE_0.html
- Bob Clark