NASA’s Curiosity rover has discovered proof of a carbon cycle on historical Mars, bringing scientists nearer to a solution on whether or not the planet was ever able to supporting life.
Curiosity sees its tracks receding into the space at a website nicknamed Ubajara on April 30, 2023; this website is the place the rover made the invention of siderite. Picture credit score: NASA / JPL-Caltech / MSSS.
Planetary researchers have lengthy believed that Mars as soon as had a thick, carbon dioxide-rich environment and liquid water on the planet’s floor.
That carbon dioxide and water ought to have reacted with Martian rocks to create carbonate minerals.
Till now, although, rover missions and near-infrared spectroscopy evaluation from Mars-orbiting satellites haven’t discovered the quantities of carbonate on the planet’s floor predicted by this principle.
“We’re finally attempting to find out whether or not Mars was ever able to supporting life – and our newest paper brings us nearer to a solution,” mentioned lead writer Dr. Benjamin Tutolo, a researcher on the College of Calgary.
“It tells us that the planet was liveable and that the fashions for habitability are appropriate.”
Utilizing knowledge collected by Curiosity, Dr. Tutolo and his colleagues analyzed the composition of an 89-m stratigraphic part of Gale crater — which as soon as contained an historical lake.
They recognized an iron carbonate mineral known as siderite in excessive concentrations — starting from roughly 5% to over 10% by weight — inside magnesium sulfate-rich layers.
This was surprising, as a result of orbital measurements had not detected carbonates in these layers.
Given its provenance and chemistry, the researchers infer that the siderite fashioned by water-rock reactions and evaporation, indicating that carbon dioxide was chemically sequestered from the Martian environment into the sedimentary rocks.
If the mineral composition of those sulfate layers is consultant of sulfate-rich areas globally, these deposits include a big, beforehand unrecognized carbon reservoir.
The carbonates have been partially destroyed by later processes, indicating that among the carbon dioxide was later returned to the environment, forming a carbon cycle.
“The invention of considerable siderite in Gale crater represents each a stunning and vital breakthrough in our understanding of the geologic and atmospheric evolution of Mars,” Dr. Tutolo mentioned.
“Drilling by way of the layered Martian floor is like going by way of a historical past guide,” added co-author Dr. Thomas Bristow, a researcher at NASA’s Ames Analysis Heart.
“Just some centimeters down offers us a good suggestion of the minerals that fashioned at or near the floor round 3.5 billion years in the past.”
The findings seem within the journal Science.
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Benjamin M. Tutolo et al. 2025. Carbonates recognized by the Curiosity rover point out a carbon cycle operated on historical Mars. Science 388 (6744): 292-297; doi: 10.1126/science.ado9966
