for National Geographic News
A year ago today scientists erupted in riotous applause when a robotic rover named Opportunity safely bounced to a stop on Mars. Today, long after the end of its 90-day initial mission, the rover continues to dazzle the world with insight into Mars's wet past.
"I never, ever would have imagined the opportunity to literally be standing here a year later and saying yet again, 'We're back, and we're still on Mars,'" departing NASA administrator Sean O'Keefe told reporters gathered for a celebration earlier this month. The occasion was to mark the one-year anniversary of the successful landing and deployment of Spirit, Opportunity's twin rover which plopped down on to the opposite side of the red planet on January 3, 2004.
The rovers were sent to Mars to hunt for signs that watera key ingredient in the recipe for lifeonce existed on the planet. With the support of satellites in Mars orbit and an army of scientists on Earth, the rovers didn't disappoint.
Examining a variety of Martian rocks with drills, magnifying glasses, and a suite of high-tech sniffers, the rovers have found minerals, chemical signatures, and rocks with textures and shapes that are suggestive of a watery past.
"[The] discovery that Mars once had a large amount of surface water is indeed a profound finding," O'Keefe said. "And what it tells us is that the climate, the atmosphere of our closest neighbor, was once dramatically different and perhaps conducive to life."
Steve Squyres, the Cornell University-based principal investigator for the Mars Exploration Rover Mission, was at JPL for the celebration. He concurred that the year's events and discoveries have been remarkable.
"I think, by any reckoning, the lasting legacy of this mission is going to turn out to be the recognition by people here on this planet that our sister planet Mars once had habitable conditions on its surface," he said. "And what that meant for the origin of life, what it meant for the evolution of lifethat's for the future Mars program to tell."
The rovers were designed to work for 90 days and to travel little more than half a mile (one kilometer). They've far exceeded those parameters and will continue to operate until some mission-ending mishap occurs, according to program scientists.
"These rovers are in great shape for their age right now," said Jim Erickson, project manager of the Mars Exploration Rover Mission at JPL. "As they continue on through their respective anniversaries, they're continuing to get new records under their belt."
A year into their exploration, the rovers have driven nearly four miles (six kilometers) and combined and sent to Earth more than 62,000 images and reams of additional science data.
Spirit's only major "health" crisis came eight days after it bounced to a stop in Gusev Crater. A glitch in its memory software left the rover silent. But mission engineers were able to update the software and send the rover on its way.
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