Mars Rovers Break Driving Records, Examine Salty Soil - March 02, 2005

Spirit, meanwhile, has uncovered soil that is more than half salt, adding to the evidence for Mars' wet past. The golf-cart-size robots successfully completed their three-month primary missions in April 2004 and are continuing extended mission operations.

Courtesy NASA/JPL-Caltech

"Tyrone"

Salty Expression (False Color) - January 20,-2006

Spirit uncovered several types of materials distinctive in their color, physical properties and chemistry as a result of accidentally digging a trench 30 centimeters (11.8 inches) wide during a turn at the end of a drive. The white material in this image is brighter than any seen previously by the rover. It has a powdery and cloddy texture and exhibits a high abundance of salts. The materials appear similar in some ways to bright soil deposits seen back at the "Paso Robles" site that Spirit encountered on the rover's Martian day, or sol, 431 (March 20, 2005) while climbing the northern flank of "Husband Hill."

Spirit analyzed the bright, yellowish exposures in the lower left part of the frame using instruments on the rover's robotic arm. Scientists hypothesized and then confirmed that these materials have a salty chemistry dominated by iron-bearing sulfates. These salts may record the past presence of water, as they are most easily mobilized and concentrated in liquid solution. Spirit also examined the unusual, pitted rock about 10 centimeters (4 inches) wide in the lower center of the frame. Scientists continue to study the origin of these rocks and soils and the role that water has played in their formation.
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Courtesy NASA/JPL-Caltech

"McCool Hill"

Bright Soil Near 'McCool': Salty Deja Vu? - March 23, 2006

While driving eastward toward the northwestern flank of "McCool Hill," the wheels of NASA's Mars Exploration Rover Spirit churned up the largest amount of bright soil discovered so far in the mission. This image from Spirit's navigation camera, taken on the rover's 787th Martian day, or sol, of exploration (March 21, 2006), shows the strikingly light tone and large extent of the deposit.

These discoveries indicate that light-toned soil deposits might be widely distributed on the flanks and valley floors of the "Columbia Hills" region in Gusev Crater on Mars. The salts may record the past presence of water, as they are easily mobilized and concentrated in liquid solution.

Image PIA08618.jpg Courtesy NASA/JPL Click on image for large size

NASA: SOL 723 Gallery

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