WASHINGTON, March 2 (UPI) -- NASA scientists said Tuesday the Opportunity rover has discovered evidence the Martian surface once was soaking wet with water.
The rover, which touched down inside a small crater in an area called Meridiani Planum on Jan. 24, has uncovered evidence of minerals that are known only to form in the presence of liquid water.
"Liquid water once drenched the surface," said Dr. Steve Squyres of Cornell University, Ithaca, N.Y., principal investigator for the science instruments on Opportunity and its twin, Spirit.
"We've been able to read the tell-tale clues the water left behind, giving us confidence in that conclusion."
Squyres noted, however, so far scientists are unable to determine whether the minerals formed as sedimentary deposits from standing pools or lakes of water, or whether they accumulated through the action of groundwater. Further study will be necessary to make that determination, he said.