spacetoday.net: Mars rovers finds soil consistent with liquid water

Posted: Sat, Feb 21, 2004, 10:13 AM ET (1513 GMT)
Mars Exploration Rover (NASA/JPL)

Sticky, fine-grained soil found at the landing sites of the twin MArs rovers Spirit and Opportunity may be consistent with, but not necessarily proof of, salty liquid water near the surface. Planetary scientists involved with the mission noted that soil in the Gusev Crater landing site tends to stick to the wheels of the rover Spirit. That stickiness could be explained if the soil was very fine-grained, but could also be evidence of salts left over from a brine that may still exist below the surface. Mission controllers plan to use Spirit's wheels to dig a trench similar to the one made recently by Opportunity on the other side of the planet so see what conditions are like several centimeters below the surface. Opportunity's trench revealed clumps of soil on the sides; scientists aren't sure what holds the clumps together. Images from Opportunity have also revealed fine threads of material on the surface that scientists and engineers believe is fabric from the lander's airbags.