A NASA robot has found more building blocks for life on Mars, the most complex organic matter yet from 3.5 billion-year-old rocks on the surface of the red planet, the USA space agency said on Thursday.
"That the Curiosity rover recovered organics from a drilled mudstone sample is a game changer for Mars life studies".
The data gathered by Curiosity reveal that billions of years ago there was a shallow lake of water inside the Gale Crater on Mars that contained all the ingredients necessary for life as we know it, including chemical building blocks and energy sources.
The discovery is a fascinating development in the search for life outside Earth and serve as a clue for researchers about the history of the Red Planet.
The rover also collected information about the varying levels of methane in the atmosphere of Mars. Methane is also produced by non-biological sources though, and while those organic molecules could have enabled life to form they also might not have.
In this regard, Jennifer Eigenbrode, of NASA's Goddard Space Center in Maryland (USA), said finding organic molecules in the first five centimeters of rock deposited when Mars could have been habitable, "is a good omen for future missions that will deepen more". It previously found hints of methane and organic compounds, but these findings are the best evidence yet.
However, all this does not prove that there is or ever was life on Mars. Methane levels were measured over a period of 4.5 years, which showed an increase of methane during late winter in the southern hemisphere and late summer in the northern hemisphere.
This is not the first time that Curiosity has detected organic molecules, but previous measurements were considered unreliable because of possible sample contamination and unwanted chemical reactions. Although there was no way to directly date the organic material found within the rocks, it has to be at least as old as the rocks themselves. "And it makes us more confident that if biomarkers" - or direct evidence of biologic activity - "are there, we might find them".
The details about the research will also be published on Thursday in Science- which is one of the top scientific journals.
"We have no proof that the methane is formed biologically, but we can not rule it out, even with this new data set", Webster said. "There were signals there that were telling us that we had detected certain types of organic molecules", she says.
Webster theorizes the methane created either now or long ago is seeping from deep underground reservoirs up through cracks and fissures in the crust. If you're interested in being part of the conversation, or have a burning question that you'd like NASA to answer, you can submit inquiries using the hashtag #askNASA up until 1 p.m. this afternoon.
Scientists have been seeking organic molecules on Mars ever since the 1976 Viking landers.