If Mars were a fruit in the produce aisle (and, let’s be honest, it would make a decent-looking nectarine), NASA could slap an organic sticker on it. Kind of.
Researchers at the space agency announced Thursday that the Curiosity rover has discovered strong concentrations of organic molecules in 3-billion-year-old sedimentary rocks on the red planet’s surface. Those molecules are familiar building blocks for life here on Earth, including carbon, hydrogen, oxygen and nitrogen.
That doesn’t mean they’ve found life, but it’s a good indication Mars could have sustained life in the past. While Curiosity encountered organic carbon on the planet’s surface back in 2012 and again in 2013, NASA said Thursday this most recent find was in concentrations 100 times greater than earlier detections.
“Curiosity has not determined the source of the organic molecules,” cautioned Jen Eigenbrode of NASA’s Goddard Space Flight Center in a NASA release. Eigenbrode is the lead author on a paper presenting the discovery in the June 8 edition of the journal Science.
“Whether it holds a record of ancient life, was food for life, or has existed in the absence of life,” Eigenbrode continued, “organic matter in Martian materials holds chemical clues to planetary conditions and processes.”
The organic-rich sample came from the bottom of what used to be a massive lake inside Gale Crater billions of years ago. That’s particularly exciting since water ― so far as we know ― is also an essential ingredient for life.
And in a separate report in Science set to publish Friday, scientists revealed the Curiosity rover has also detected methane on the Martian surface in concentrations that vary with the seasons. The methane concentrations peak near the end of the northern hemisphere’s summer, then dwindle in the winter.
The methane could simply be the product of basic geological processes, but it’s possible the gas has origins in biological sources.