NASA Mars Opportunity discovers clays favourable to Martian biology

The pale rock in the upper center of this image, about the size of a human forearm, includes a target called “Esperance,” which was inspected by NASA’s Mars Exploration Rover Opportunity.

Data from the rover’s alpha particle X-ray spectrometer (APXS) indicate that Esperance’s composition is higher in aluminum and silica, and lower in calcium and iron, than other rocks Opportunity has examined in more than nine years on Mars. 

Preliminary interpretation points to clay mineral content due to intensive alteration by water. 

Credit: NASA/JPL-Caltech/Cornell/Arizona 

Now nearly a decade into her planned 3 month only expedition to Mars, NASA's longest living rover Opportunity, struck gold and has just discovered the strongest evidence to date for an environment favourable to ancient Martian (organic) biology – and she has set sail hunting for a motherlode of new clues amongst fabulous looking terrain.

Barely two weeks ago in mid-May 2013, Opportunity's analysis of a new rock target named "Esperance" confirmed that it is composed of a "clay that had been intensely altered by relatively neutral pH water – representing the most favorable conditions for biology that Opportunity has yet seen in the rock histories it has encountered," NASA said in a statement.

The finding of a fractured rock loaded with clay minerals and ravaged by flowing liquid water in which life could have thrived amounts to a scientific home run for the golf cart sized rover!

"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," said the mission's principal investigator Prof. Steve Squyres of Cornell University, Ithaca, N.Y.

Opportunity accomplished the ground breaking new discovery by exposing the interior of Esperance with her still functioning Rock Abrasion Tool (RAT) and examining a pristine patch using the microscopic camera and X-Ray spectrometer on the end of her 3 foot long robotic arm.

The robot made the discovery at the conclusion of a 20 month long science expedition circling around a low ridge called "Cape York" – which she has just departed on a southerly heading trekking around the eroded rim of the huge crater named "Endeavour."

"Esperance was so important, we committed several weeks to getting this one measurement of it, even though we knew the clock was ticking."

Esperance stems from a time when the Red Planet was far warmer and wetter billions of years ago.

Close-Up of ‘Esperance’ After Abrasion by Opportunity 

This mosaic of four frames shot by the microscopic imager on the robotic arm of NASA’s Mars Exploration Rover Opportunity shows a rock target called “Esperance” after some of the rock’s surface had been removed by Opportunity’s rock abrasion tool, or RAT. 

The component images were taken on Sol 3305 on Mars (May 11, 2013). 

The area shown is about 2.4 inches (6 centimeters) across. 

Credit: NASA/JPL-Caltech/Cornell/USGS