New Mars discoveries are advancing the case for possible life on the red planet, past or even present. Scientists reported Thursday that NASA's Curiosity rover has found potential building blocks of life in an ancient Martian lakebed. Hints have been found before, but this is the best evidence yet, the AP reports. The organic molecules preserved in 3.5 billion-year-old bedrock in Gale Crater—believed to once contain a shallow lake the size of Florida's Lake Okeechobee—suggest conditions back then may have been conducive to life. That leaves open the possibility that microorganisms once populated our planetary neighbor and still might. "The chances of being able to find signs of ancient life with future missions, if life ever was present, just went up," said Curiosity's project scientist, Ashwin Vasavada of NASA's Jet Propulsion Laboratory in Pasadena, California.
Curiosity also has confirmed sharp seasonal increases of methane in the Martian atmosphere. Researchers said they can't rule out a biological source. Most of Earth's atmospheric methane comes from animal and plant life, and the environment itself. The two studies appear in the journal Science. In a companion article, an outside expert describes the findings as "breakthroughs in astrobiology." "The question of whether life might have originated or existed on Mars is a lot more opportune now that we know that organic molecules were present on its surface at the time," wrote Utrecht University astrobiologist Inge Loes ten Kate of the Netherlands. Scientists agree more powerful spacecraft—and, ideally, rocks returned to Earth from Mars—are needed to prove whether tiny organisms like bacteria ever existed on the red planet.
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