NASA's Curiosity Mars rover has found a diverse mix of organic molecules on Mars, including chemicals widely considered building blocks for the origin of life on Earth. The finding marks the first time a new kind of chemical experiment has been performed on another planet.
Curiosity rover has been dutifully probing Mars' Gale crater and Mount Sharp since the robot plopped down on the Red Planet on Aug. 6, 2012. The car-sized Mars rover is now wheeling about in the Glen Torridon region of Gale crater, a place that scientists believe could have supported conditions that were favorable to supporting ancient life, if it was ever there in the first place. While in the region, Curiosity recently utilized its onboard Sample Analysis at Mars (SAM) instrument suite, built to search for compounds of the element carbon that are associated with life and investigate ways in which these compounds are generated and destroyed in the Martian ecosphere.
Curiosity's SAM instrument was able to use a chemical known as tetramethylammonium hydroxide (TMAH) to detect organic molecules in the region's clay-rich sandstone. The newly identified chemicals include nitrogen and sulfur-bearing molecules that are similar to the raw material that helped spur life on Earth. However, the experiment can't tell if the chemicals come from ancient Martian life or non-biological geological processes.
The study of Curiosity's first SAM TMAH experiment was led by Amy Williams, an associate professor in the Department of Geological Sciences at the University of Florida in Gainesville. The research has been published in the journal Nature Communications.
"This experiment and its results have been a labor of love and science," Williams told Space.com. "This was the first time that TMAH had been used on another world and our team worked extensively to interpret and confirm the molecules detected in this first-of-its-kind experiment."
Clay-bearing sandstones
Curiosity's experiment detected more than 20 organic molecules from clay-bearing sandstones in the roughly 3.5-billion-year-old Knockfarrill Hill section of Glen Torridon. The variety of organic molecules observed suggests that some chemical diversity has been preserved in ancient Martian sediments despite billions of years of diagenesis (the process by which sediment turns to rock) and radiation exposure.
"We propose that this suite of organics represents TMAH thermochemolysis breakdown products from ancient organic macromolecular material that has been preserved in billions-of-years-old sedimentary rocks in Gale crater," explains the research paper.
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