Rocks on Mars still harbour organic molecules after billions of years

NASA conference Mars Curiosity Rover

NASA conference Mars Curiosity Rover

The Curiosity rover found organic material and mysterious methane on Mars that suggest evidence that the planet could have supported ancient life, NASA announced Thursday.

These newly-found ancient organics, ten Kate said, serve to confirm that the basic conditions for life to form really did exist on Mars 3.5 billion years ago, and that there wasn't any outside force (say, ultraviolet light) powerful enough to destroy them entirely.

NASA will host a discussion and announce a discovery made by its Mars rover Curiosity on Thursday.

Water-rock chemistry might have generated the methane, but scientists can not rule out the possibility of biological origins. The organic molecules were found in Gale Crater - believed to once contain a shallow lake the size of Florida's Lake Okeechobee. That's because the surface of Mars is constantly bombarded with radiation that can break down organic compounds. "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. Now Curiosity shows that these carbon-based compounds do indeed exist.

By examining data spanning almost three Martian years (six Earth years), Webster and his colleagues discerned the first repeating pattern in Martian methane.

Danny Ainge Reveals Why Kyrie Irving Wasn’t At Game 7
The Celtics still have things they need to figure out, making sure they can be at their best when the regular season starts. Imagine waking up drenched in sweat from a bad dream and having to relive it every night for the next decade.

Questions remain, however, as to how the organic material was formed. "While we don't know the source of the material, the incredible consistency of the results makes me think we have a slam-dunk signal for organics on Mars", Eigenbrode said. The rock samples were analyzed by SAM, which uses an oven to heat the samples (in excess of 900 degrees Fahrenheit, or 500 degrees Celsius) to release organic molecules from the powdered rock. This could be a sign that there is a reservoir of methane somewhere under the surface that was generated by chemical reactions involving water or, possibly, by Martian microbes. The latter element, it is thought, came from a sulfur-rich mineral called jarosite that previous Curiosity investigations had revealed in 3.5-billion-year-old deposits in Gale Crater-laid down at a time when the crater was warm, wet and apparently habitable.

Curiosity rover on Mars. Curiosity sampled mudstone in the top 5 centimeters from the Mojave and Confidence Hills localities within Gale Crater.

Now, with years of Curiosity's atmospheric readings at their disposal, Webster and his colleagues were able to analyze 55 Earth months (or roughly three Martian years) of data, finding that there were indeed low levels of background radiation - and that it seemed to experience seasonal surges, almost tripling at its peak near summer's end in the northern hemisphere (and winter's end in the south).

Paul Mahaffy, director of the Solar System Exploration Division at NASA's Goddard Space Flight Center in Greenbelt, Maryland, explained that the objective of the mission was to explore the possibility of sustaining life on Mars. That's particularly exciting since water ― so far as we know ― is also an essential ingredient for life. We might find even more evidence in future missions, too.

Webster and his colleagues suspect that the methane comes from deep underground, and temperature swings on Mars's surface throttle its flow upward. They're considered necessary for life to form, but there are plenty of places with lots of organic compounds but no life.

Recommended News

We are pleased to provide this opportunity to share information, experiences and observations about what's in the news.
Some of the comments may be reprinted elsewhere in the site or in the newspaper.
Thank you for taking the time to offer your thoughts.