NASA's rover Curiosity has found organic compounds on Mars, the first definitive proof of materials on the Red Planet that, on Earth, are building blocks for life.
"We have had a major discovery. We have found organics on Mars," Curiosity lead scientist John Grotzinger, with the California Institute of Technology in Pasadena, Calif., said during a webcast press conference at the American Geophysical Union conference in San Francisco.
Whether the organics were delivered by carbon-rich meteorites or formed on Mars has yet to be determined.
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The discovery, paired with a sister investigation that found occasional spikes of methane gas in the Martian atmosphere, is a turning point for the mission, which began 2.5 years ago inside a 96-mile wide impact basin named Gale Crater.
On Earth, more than 90 percent of the atmospheric methane is produced by biological processes. The rest is tied to geochemical processes.
Mars missions used to be ones "where you observe and seek to explain, what I like to call the ‘Star Trek' mode -- build a spacecraft, go out there, find cool things that nobody saw before. Mars is now becoming a proving ground for a much more deductive line of science," Grotzinger said.