Opportunity, the Mars rover, has finished a 20-month long survey of the Cape York region of the Red planet with a study of a clay rock which appears to have been molded by intense water activity.
The rock, named Esperance, has provided researchers with further evidence that Mars once had an active water system. Confirming that Mars once had large quantities of water lends credence to the idea that the planet may have once harbored life.
NASA devoted a good deal of time to exploring this one rock, which is about the size of a human forearm. Differing from other rocks found during the course of Opportunity's nine-year mission, Esperance is low in calcium and iron, and rich in silica and aluminum. Researchers working on the project believe that the large clay mineral content in the structure was formed by the action of an active water body on the planet's surface.
The tool used to reveal this data was the APXS, or alpha particle X-ray spectrometer. The measurements were taken after the rover scratched away part of the outer layer of the rock using the equipped rock abrasion tool, or RAT.
Steve Squyres of Cornell University, where esteemed astronomer Carl Sagan once taught, said, "Esperance was so important, we committed several weeks to getting this one measurement of it, even though we knew the clock was ticking."
When the inner layers of the rock were examined by both a camera and spectrometer, evidence of past conditions on Mars which could have supported life became more apparent.
Squyres said, "Water that moved through fractures during this rock's history would have provided more favorable conditions for biology than any other wet environment recorded in rocks Opportunity has seen."
The Mars probe, launched in 2003, will soon set out to its next location for study, Solander Point. It is there that the Mars rover, now the oldest operational probe on the planet, will spend the Martian winter. This new area, like Cape York, makes up part of the rim of the 14-mile-wide Endeavour Crater. It is hoped that the northerly tilt of the new location will help provide power to the rover's solar arrays through the winter months.
