Spirit, Opportunity Still Roving Mars
Copyright 2004 P.G. Publishing Co.
By Dan Malerbo, Henry Buhl Jr.
The twin rovers that successfully completed their three-month primary missions on Mars in April are continuing to return new evidence of Mars’ watery past during their extended missions.
NASA engineers at the Jet Propulsion Laboratory in Pasadena, Calif., report that Spirit and Opportunity are still in good condition and providing more information to scientists.
Opportunity was the first rover to discover that an ancient body of salt water once existed on Mars when it explored a rock outcrop in Eagle Crater.
It’s now exploring the southern inner slope of the stadium-sized Endurance Crater. Opportunity has explored rock layers from the rim of the crater down to its oldest accessible layers. Scientists have discovered different compositions in different layers of rock. Magnesium and sulfur declined almost parallel with each other in the older layers, leading scientists to believe these two elements may have been dissolved and removed by water.
Small, gray stone spheres called “blueberries” were also discovered in abundance at Endurance Crater just as they were at Eagle Crater. Scientists believe the iron minerals are hematite, which usually forms in a wet environment on Earth.
After driving for six months across a Martian plain to reach bedrock at a rock outcrop called Clovis in Gusev Crater, Spirit has also returned evidence that water may once have been active on the surface of Mars. The rock here was discovered to be softer than other rocks studied so far at Gusev Crater. Spirit easily bored a hole into it with its rock abrasion tool. An analysis of the interior of the hole, made with the rover’s instruments, found high concentrations of sulfur, bromine and chlorine. This might indicate that Clovis was chemically altered, and that fluids once flowed through the rock depositing these elements.
Spirit completed observations at Clovis and is now exploring other sites.
To get the latest news and images from NASA’s twin robotic explorers, log onto http://marsrovers.jpl.nasa.gov.
Copyright 2004 P.G. Publishing Co.
Copyright © 2002 LexisNexis, a division of Reed Elsevier Inc.
