Mars Rover Enters Ninth Year with New Discoveries
Washington - The exploration rover Opportunity entered its ninth year on Mars January 25, and a newly begun mission is already yielding new findings about the Red Planet.
In eight years, the golf-cart sized craft has traveled almost 35 kilometers across Mars, examining the landscape and taking samples of rock and surface dust. In August 2011, the craft arrived at the Endeavour Crater, so named by Opportunity's handlers back on Earth at NASA's Jet Propulsion Laboratory (JPL). This bit of real estate is different from any other the craft has surveyed so far, and is giving scientists a look at the oldest geological deposits from Martian history yet sampled.
"It's like starting a new mission," said Rover Program Manager John Callas, at JPL in California, "and we hit pay dirt right out of the gate."
The first outcrop that Opportunity examined at Endeavour revealed a high zinc content, suggesting the effects of water. Opportunity also spotted a mineral vein, and identified it as hydrated calcium sulfate, which is "the clearest evidence for liquid water on Mars that we have found in our eight years on the planet," said Steve Squyres of Cornell University in New York, the mission's principal investigator.
Opportunity is settling in a on a rock outcrop in the crater, remaining on a sun-facing slope so that its solar panels will receive enough energy to continue its work through the Martian winter. Martian years are about twice the length of Earth's year, so Opportunity will remain in this position until mid-2012. The JPL team is counting on winter winds to sweep surface dust off the solar panel, allowing a solid energy recharge. When that is achieved, the researchers plan to drive Opportunity to another site where clay minerals might be found, according to earlier observations.
The current vantage point and the stationary position will also allow the craft to observe how the wind, the most active process on the planet, changes the landscape. Opportunity will also be sending back steady radio signals, which JPL scientists will be able to use to measure the planet's rotation. Those findings, in turn, may allow some inferences about the interior of Mars.
Opportunity landed on Mars in January 2004 for what was expected to be a three-month mission. The craft identified evidence of an ancient wet environment, achieving the primary mission and its other initial goals. Since then the JPL team has guided the rover to investigate larger and deeper craters, accumulating more evidence about the wet and dry periods in Mars history.
Opportunity had a partner in 2004, a twin craft called Spirit that landed halfway around the planet. Spirit also performed longer than initially expected, but stopped communicating in March 2010.
(Distributed by the Bureau of International Information Programs, U.S. Department of State.)
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