Science

Rocks on Mars still harbour organic molecules after billions of years

Rocks on Mars still harbour organic molecules after billions of years

"And then we went, 'oops, not only did we not find it, but we don't really know what we're looking for if it's not exactly like Earth.' And maybe that was not the best way to go about it".

That said, the agency hopes future missions to the red planet, NASA's Mars 2020 rover and ESA's ExoMars rover, could delve into these findings and reveal the complete history of our neighboring planet.

Curiosity also has confirmed seasonal increases of methane in the Martian atmosphere.

While this might be taken as a signature of biological activity - the main producers of methane on Earth are termites and bovine gut bacteria - non-biological mechanisms, such as weathering of Martian rocks or release from ancient ice, are possible too.

For those reasons, ten Kate said, the methane variation is the more exciting finding. Both studies resulting from the mission were published online today in the journal Science.




Experts have hailed the two new studies as milestones for 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 that time". It has also found evidence in Mars' atmosphere, relating to the search for current life on the red planet. Only a few of the organic molecules, sulfur-bearing carbon rings called thiophenes, were abundant enough to be detected directly, Eigenbrode says.

The source is still unclear, but it may be stored in the cold Martian subsurface in water-based crystals called clathrates, researchers said. "It tells us that this ancient environment on Mars could have supported life", Eigenbrode said.

By examining data spanning almost three Martian years (six Earth years), Webster and his colleagues discerned the first repeating pattern in Martian methane. The magnitude of these seasonal peaks - by a factor of three - was far more than scientists expected. "It's tripling ... that's a huge, huge difference". 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. The diameter is slightly smaller than a US dime. The gas creeps from below the surface up to be released into the Mars atmosphere via riverbeds, cracks, and crevices in the surface of the planet. The scientists said it is premature to know whether or not the compounds were created in biological processes. And Curiosity dug a little deeper beneath the surface, which is blasted with radiation, to see what stories the soil had to tell. At a minimum, the study shows how traces of bygone martians could have survived for eons-if they existed at all-and it hints at where future rovers might look for them. The key samples in the latest findings came from a spot 6.4 kilometres away. The organic material discovered on Mars is rich in sulphur, which would have also helped to preserve it. The Martian surface is bombarded with radiation that can degrade organic compounds, explains Eigenbrode.

MIT News checked in with SAM team member Roger Summons, the Schlumberger Professor of Geobiology at MIT, and a co-author on the Science paper, about what the team's findings might mean for the possibility of life on Mars.