Mars Curiosity rover. (NASA via SWNS)
By Stephen Beech
Large carbon deposits have been found on Mars, suggesting it was once home to alien lifeforms.
NASA’s Curiosity Rover discovered evidence of a carbon cycle below the Red Planet's surface.
The find brings researchers closer to answering the question about whether Mars was ever capable of supporting life.
Scientists are working to understand climate transitions and habitability on ancient Mars as Curiosity explores Gale Crater.
The latest findings, published in the journal Science, reveal that data from three of Curiosity’s drill sites had siderite, an iron carbonate material, within sulphate-rich layers of Mount Sharp in Gale Crater.
Study lead author Dr. Ben Tutolo, of the University of Calgary in Canada, said: “The discovery of large carbon deposits in Gale Crater represents both a surprising and important breakthrough in our understanding of the geologic and atmospheric evolution of Mars."
Planet Volumes
Dr. Tutolo, a participating scientist on the NASA Mars Science Laboratory Curiosity Rover team, explained that reaching the strata was a long-term goal of the mission.
He said: “The abundance of highly soluble salts in these rocks and similar deposits mapped over much of Mars has been used as evidence of the ‘great drying' of Mars during its dramatic shift from a warm and wet early Mars to its current, cold and dry state."
Sedimentary carbonate has long been predicted to have formed under the carbon dioxide-rich ancient Martian atmosphere, but Dr. Tutolo says identifications had previously been sparse.
NASA’s Curiosity Rover landed on Mars in August 2012, and has since travelled more than 20 miles (34 km) across the planet's surface.
Scientists say the discovery of carbonate suggests that the atmosphere contained enough carbon dioxide to support liquid water existing on the planet’s surface.
As the atmosphere thinned, the carbon dioxide transformed into rock form.
Illustration of NASA’s Perseverance Mars rover. (NASA/JPL-Caltech via SWNS)
NASA says future missions and analysis of other sulphate-rich areas on Mars could confirm the findings and help to better understand the planet’s early history and how it transformed as its atmosphere was lost.
Dr. Tutolo says scientists are ultimately trying to determine whether Mars was ever capable of supporting life, and the latest paper brings them closer to an answer.
He said: “It tells us that the planet was habitable and that the models for habitability are correct.
“The broader implications are the planet was habitable up until this time, but then, as the CO2 that had been warming the planet started to precipitate as siderite, it likely impacted Mars’ ability to stay warm.
“The question looking forward is how much of this CO2 from the atmosphere was actually sequestered?
"Was that potentially a reason we began to lose habitability?”
NASA
Dr. Tutolo says the latest research tie in with his ongoing work on Earth, trying to turn anthropogenic CO2 into carbonates as a climate change solution.
He said: “Learning about the mechanisms of making these minerals on Mars helps us to better understand how we can do it here.
“Studying the collapse of Mars’ warm and wet early days also tells us that habitability is a very fragile thing.”
Dr. Tutolo says it’s clear that small changes in atmospheric CO2 can lead to "huge changes" in the ability of the planet to harbour life.
He added: “The most remarkable thing about Earth is that it’s habitable and it has been for at least four billion years.
“Something happened to Mars that didn’t happen to Earth.”
