NASA to look out wet land at Mars for next mission

Washington, Oct 20: The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on board NASA"s Mars Reconnaissance Orbiter is helping astronomers scout potential landing sites for NASA's next Mars rover mission.

The powerful mineral-mapping camera has mapped 125 new images of possible landing sites on the Red Planet. RISM principal investigator Dr. Scott Murchie has said since the 2009 Mars Science Laboratory (MSL) “will assess whether Mars ever had an environment capable of supporting life, it will have to land in an area with a mineral record indicative of past water".

CRISM is critical to the selection process because it is the only instrument on MRO with the spectral power to 'see' the chemical makeup of the rocks," he said.

Dr. Murchie said one of CRISM"s main mission objectives is to find and investigate areas that were wet long enough to leave a mineral signature.

He said CRISM offered greater capability to map spectral variations than any similar instrument sent to another planet. It could read 544 “colours" of reflected sunlight to detect minerals in the surface, he said.
Dr. Murchie said the imaging spectrometer is among MRO's cadre of advanced sensors studying Mars in unprecedented detail and contributing to the MSL landing site selection effort.

He said this included correlating CRISM"s spectral data with high-resolution pictures of boulders, craters, sediment layers and other surface features acquired by the High Resolution Imaging Science Experiment (HiRISE) and Context Camera (CTX).

“CRISM images provide the scientific criteria that will allow the MSL team to narrow its choices. By combining data from the MRO instruments, we can create a complete picture of the Martian surface," said Dr. Murchie.

Dr. Murchie said the CRISM data release consisted of user-friendly, colour-coded, thematic images.

Different versions of each image showed clays, sulphates, and unaltered minerals that told the story of past water and volcanic processes on Mars, he said.

He said the set also included infrared images of surface brightness and enhanced visible-colour composites. Each image covered a square area roughly 6 miles (10 kilometres) on a side, with a spatial resolution of approximately 66 feet (20 meters) per pixel, he added.

“The data products that we have generated for all the proposed MSL landing sites are scaled in a similar manner. This should make it easy for scientists and the public alike to distinguish between landing sites that possess a wide range of rock types, from ones that do not," said Dr. Olivier Barnouin-Jha from Johns Hopkins University Applied Physics Laboratory (APL).

So far, CRISM has mapped more than half the planet in its low-resolution mode since MRO"s two-year science mission began in November 2006. In addition, it has made more than 2,500 high-resolution observations of the surface and nearly 3,000 atmospheric observations.

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