|'Two for Two': Opportunity Lands on Mars||
Image Left: Ground controllers celebrate at NASA's Jet Propulsion Laboratory in Pasadena, California.
Just three weeks after NASA's Spirit rover touched down on Mars, its twin Opportunity joined it on the red planet, landing shortly after midnight eastern time on Sunday, January 25.
Ground controllers at NASA's Jet Propulsion Laboratory erupted in cheers and applause, a replay of the celebration following the Spirit landing.
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NASA Administrator Sean O'Keefe led off a post-landing press conference with praise for the Mars Exploration Rover team, which he called "the best in the world."
Mars Exploration Rover Project Manager Peter Theisinger summed up the emotion of the night with a simple phrase: "We are two for two."
Administrator O'Keefe also pointed to engineers' success in dealing with a communications problem with Spirit that developed earlier in the week.
Just hours before Opportunity landed, engineers found a way to communicate reliably with Spirit and they're working to get Spirit's computer out of a cycle of rebooting many times a day.
Dr. Ed Weiler, NASA's Associate Administrator for Space Science, noted that the last few days have been an emotional rollercoaster for the Mars team. But, he said, "we resurrected one rover and saw the birth of another." Weiler also cautioned that Opportunity's landing is just "one more critical milestone" in the mission.
Opportunity's landing site is on plains called Meridiani Planum within an Oklahoma-sized outcropping of gray hematite, a mineral that -- on Earth -- usually forms in the presence of water.
Scientists plan to use the research instruments on Opportunity to determine whether the gray hematite layer comes from sediments of a long-gone ocean, from volcanic deposits altered by hot water or from other ancient environmental conditions.