NASA rover finds more clues of past water on Mars ; Spirit, Opportunity compile a panoramic photograph of planet
PASADENA — NASA’s Spirit rover uncovered more evidence of past water activity on Mars, although not in the large amounts its twin rover Opportunity has found halfway around the planet, mission scientists said Thursday.
Spirit found limited amounts of water altered a volcanic rock nicknamed Mazatzal, coursing through tiny fissures that crisscross the boulder and cementing together the multiple layers that mask its surface.
The findings were made during a weeklong analysis of the rock in the Gusev Crater region where Spirit landed Jan. 3.
Since then, Spirit has been overshadowed by Opportunity as it found signs that extensive water, possibly a salty sea, once covered its landing site on Meridiani Planum.
Hap McSween, a science team member from the University of Tennessee, Knoxville, said Spirit’s find “may be the best we can do at Gusev.”
“Evidence of water at Gusev Crater has been hard to come by,” McSween told a Jet Propulsion Laboratory news conference.
Scientists used Spirit’s combination brush and drill to bore into Mazatzal, creating in one instance a daisy pattern.
The grinding revealed at least three distinct layers to the rock as well as hairline cracks filled with altered materials. Tiny quantities of water likely played a role in forming all the features, although exactly how remains unknown, scientists said.
“This is not water that sloshed around the surface, as it apparently did at Meridiani. We’re talking about small amounts of water possibly in the ground,” McSween said.
Together, the rovers have taken more than 20,000 photographs, including a massive mosaic of 558 individual images that Opportunity snapped from outside the small crater in which it landed Jan. 24.
The so-called “Lion King panorama” continues to trickle back to Earth, where it’s being assembled, said Cornell University astronomer Jim Bell as he showed off a sliver of the full picture.
“It was named that after that famous scene in the Disney movie where the monkey is holding the little lion out over — perched over — the precipice and kind of like our rover, perched over this incredible crater, this incredible panorama,” Bell said.
NASA scientists had hoped Spirit would find lake deposits on the plains at Gusev. Instead, they now know Gusev is scattered with volcanic rocks repeatedly churned by countless impacts in the distant past.
On Thursday, Spirit struck out on a roughly 1.2-mile drive toward a cluster of hills that may preserve evidence of the lake thought to once have filled the basin.
The rover covered the first 120 feet of its journey, which could take another 30 to 50 days to complete, flight director Chris Lewicki said.
Spirit concludes its 90-day planned mission this week, but it and Opportunity both should last through the summer, mission members said.
Other than a computer file problem on Opportunity, neither rover is showing any signs of wear or tear, Lewicki said. ——
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