A mineral called Siderite who was found abundantly in rock drilled by a NASA rover on the surface of Mars, provides new proof of the warmer and wetter old past of the planet when it had considerable water bodies and possibly cherished life.
The Curiosity Rover, who landed on Mars in 2012 to investigate whether the planetary neighbor of the Earth was once able to support the microbial life, found the mineral in rock samples drilled at three locations in 2022 and 2023 in Gale Crater, a large impact basin with a mountain in the middle.
Siderite is an iron carbonate mineral. His presence in sedimentary rocks formed, billions of years ago provides proof that Mars once had a dense atmosphere that was rich in carbon dioxide, a gas that the planet would have heated through the greenhouse effect to the point that the bodies of liquid water could maintain on the surface.
There are characteristics on the landscape of Mars that many scientists have interpreted as signs that liquid water once flowed over the surface, with potential oceans, lakes and rivers that were considered possible habitats for the past of microbial life.
Carbon dioxide is the most important climate -regulating greenhouse gas on earth, such as on Mars and Venus. His presence in the atmosphere runs warmth from the sun and heats the climate.
Until now, the proof that the Mars -atmosphere was rather rich in carbon dioxide scarce. The hypothesis is that when the atmosphere, for reasons that are not fully understood, evolved from thick and rich in carbon dioxide to thin and starving from this gas, the carbon was buried by geochemical processes in rocks in the planet's crust as a mineral of the planet.
The samples obtained through curiosity, which drill 1.2 to 1.6 inches (3-4 centimeters) in rock to study the chemical and mineral composition, give weight to this idea. The samples contain up to 10.5% siderite due to weight, as determined by an instrument on board the Auto-Size, six-wheeled robber.
“One of the long -term mysteries in the study of the planetary evolution and habitability of Mars is: if large amounts of carbon dioxide were needed to heat the planet and stabilize liquid water, why are there so few detections of carbonate minerals on the Martian surface?” Said the University of Calgary -Geochemist Benjamin Tutolo, a participating scientist from NASA's Mars Science Laboratory Curiosity Rover team and main author of the study published on Thursday in the Journal Science.
“Models predict that carbonate minerals should be widespread. But to date, Rover-based examinations and satellite-based orbital surveys of the Mars surface had found little proof of their presence,” Tutolo added.
Because ROTS has been identified by the Rover worldwide on Mars worldwide, the researchers suspect that it also contains an abundance of carbonate minerals and can contain a considerable part of the carbon dioxide that once heated Mars.
The Gale crater -sedimentary rocks – sandstones and mud stones – are supposed to have been deposited about 3.5 billion years ago, when this was the location of a lake and before the Mars climate underwent a dramatic change.
“The shift of the surface of Mars from more habitable in the past, apparently sterile today, is the largest known environmental catastrophe,” said planetary scientist and is studying co-author Edwin Kite of the University of Chicago and Astera Institute.
“We do not know the cause of this change, but today Mars has a very thin carbon dioxide atmosphere, and there are indications that the atmosphere was thicker in the past. This gives a premium on the understanding of the carbon, so discovering an important unexpected deposit of carbon-rich materials is an important new indication.
The findings of the Rover offer insight into the carbon cycle on old Mars.
On earth, volcanoes carbon dioxide spit in the atmosphere and the gas is absorbed by surface waters – mainly the ocean – and combines with elements such as calcium to form limestone rocks. Due to the geological process called Plaattektoniek, this rock is re -heated and the carbon is eventually released in the atmosphere by volcanism. Mars misses, however, plays tectonics.
“The important feature of the old Martian carbon cycle that we sketch in this study is that it was unbalanced. In other words, considerably more carbon dioxide seems to have been shattered in the rocks, then it was then released in the atmosphere,” Tutolo said.
“Models of the evolution of the Martian climate can now record our new analyzes and in turn help the role of this unbalanced carbon cycle in maintaining and ultimately losing, habitability about the planetary history of Mars,” Tutolo added.
(Except for the headline, this story was not edited by Our staff and has been published from a syndicated feed.)
