For the first time since landing on Mars in August, NASA’s Curiosity rover has used its most powerful instrument to analyze soil, sifting for life-supporting chemicals with a labyrinth of ovens and spectrometers, scientists announced Tuesday.
Curiosity’s robotic arm poured a pinch of fine sand and dust into the Sample Analysis at Mars, or SAM, instrument on Friday, and the on-board laboratory studied the soil’s chemical make-up over the following two days, according to NASA’s Jet Propulsion Laboratory.
SAM is the largest scientific payload on the Curiosity rover, and researchers say it will provide the most thorough examination ever conducted on Martian soil.
Curiosity scooped soil for the sample from a sandy patch called “Rocknest” and deposited the powdery material into SAM and the adjacent CheMin instrument, which uses X-ray diffraction to identify minerals in the soil.
CheMin previously scrutinized a soil sample from Rocknest, but the analysis marked the first time scientists have used the SAM instrument on soil. Solid samples pass through two spectrometers and a gas chromatograph housed inside the microwave-sized SAM payload.
“We received good data from this first solid sample,” said Paul Mahaffy, SAM principal investigator from NASA’s Goddard Space Flight Center in Greenbelt, Md. “We have a lot of data analysis to do, and we are planning to get additional samples of Rocknest material to add confidence about what we learn.”
The sensors inside SAM examine gases and solvents extracted from powdered soil samples. SAM can detect smaller abundances of organics and identify a wider variety of them than any instrument before, according to the mission’s press kit.
A mass spectrometer inside SAM identifies gases by molecular weight and electrical charge, looking for elements important for life, including nitrogen, phosphorous, sulfur, oxygen, hydrogen and carbon, according to the press kit.
The instrument’s laser spectrometer uses light to measure methane, carbon dioxide and water vapor.
Another of SAM’s tools, a gas chromatograph, detects organic compounds by separating different gases from a mixture, according to the press kit.
SAM previously ingested Martian air to search for methane and other elements in the atmosphere, but analyses of four atmospheric samples turned up no definitive detection of methane, a signature of possible life.
By: Stephen Clark, Spaceflight Now. November 13, 2012. http://spaceflightnow.com/mars/msl/121113sam/#.UKpNX-TAchw