AKIPRESS.COM - Two landmark discoveries reveal organic carbon on the red planet, shaping the future hunt for life on Mars, National Geographic reported.
A new study published in Science on Thursday presents the first conclusive evidence for large organic molecules on the surface of Mars, a pursuit that began with NASA’s Viking landers in the 1970s. Earlier tests may have hinted at organics, but the presence of chlorine in martian dirt complicated those interpretations.
“When you work with something as crazy as a rover on Mars, with the most complex instrument ever sent to space, it seems like we’re doing what may have been perceived earlier as impossible,” says lead author Jennifer Eigenbrode, a biogeochemist at NASA Goddard. “I work with an amazing group of people on Mars, and we have discovered so much.”
Curiosity's latest data reveal that the watery lake that once filled Mars’s Gale Crater contained complex organic molecules about 3.5 billion years ago. Hints of them are still preserved in sulfur-spiked rocks derived from lake sediments. Sulfur may have helped protect the organics even when the rocks were exposed at the surface to radiation and bleach-like substances called perchlorates.
By themselves, the new results aren't evidence for ancient life on Mars; non-living processes could have yielded identical molecules. At a minimum, the study shows how traces of bygone martians could have survived for eons—if they existed at all—and it hints at where future rovers might look for them.
“This is an important finding,” says Samuel Kounaves, a Tufts University chemist and former lead scientist for NASA's Phoenix Mars lander. “There are locations, especially subsurface, where organic molecules are well-preserved.”