Special report: US twin Mars rovers land safely
WASHINGTON, Sept. 6 (Xinhua) -- NASA's Mars rover Opportunity was closing in on what may be the grandest overlook and richest science trove of its long mission, NASA announced Wednesday at its official website.
During the next two weeks, the robotic geologist – Opportunity was likely to reach the rim of a hole in the Martian surface wider and deeper than any it has visited. The crater, known as "Victoria," is approximately 750 meters wide and 70 meters deep.
Images from NASA's Mars Global Surveyor orbiter showed the crater walls expose a stack of rock layers approximately 30 to 40 meters thick.
Opportunity would send back its initial view into the crater as soon as it gets to the rim. Scientists and engineers would use Opportunity's observations from points around the rim to plot the best route for entering the crater.
Opportunity originally landed at "Eagle Crater," then moved to "Endurance Crater," where it spent six months, and "Victoria Crater" would be the third goal for the treking rover. Up to Sept. 5, the rover has been on Mars for the 930th Martian day.
"Victoria has been our destination for more than half the mission," said Ray Arvidson of Washington University, St. Louis. Arvidson is deputy principal investigator for Opportunity and its twin rover, Spirit.
He said, "Examination of the rocks exposed in the walls of the crater will greatly increase our understanding of past conditions on Mars and the role of water. In particular, we are very interested in whether the rocks continue to show evidence for having been formed in shallow lakes."
The NASA rovers have been exploring landscapes on opposite sides of Mars since January 2004. Their prime missions lasted three months. Both rovers are still investigating Mars' rocks, soils and atmosphere after more than 30 months. Opportunity works in a region where rock layers hundreds of meters or yards in thickness cover older, heavily cratered terrain.
"We have a fully functional vehicle with all the instruments working. We're ready to hit Victoria with everything we've got," said Byron Jones, a rover mission manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. Enditem
