Aqueous processes on Mars.
[The ensemble of observations show that the evidence for aqueous processes detected by the Opportunity Rover in Meridiani Planum is widespread and confirms the extended presence of surface or near-surface water over this large region of Mars. The scenarios of formation of Terra Meridiani ("dirty" acidic evaporite, impact surge or weathering of volcanic ash) cannot satisfactorily explain the mineralogy derived from the OMEGA observations.]
From: http://cat.inist.fr/?aModele=afficheN&cpsidt=20311236.
It's still cool, imho. The findings are beyound...