Latest news with #CheMin
Yahoo
22-04-2025
- Science
- Yahoo
What Happened to Mars' Lost Atmosphere? New Clues May Explain Why It Disappeared.
All evidence points to Mars having had a carbon dioxide-rich atmosphere billions of years ago, but insufficient carbonates in Martian soil challenge this theory. Now, a new study using data from NASA's Curiosity Rover claims that sulfate layers on the Martian surface may have been hiding siderite—iron carbonate—from orbital survey missions. If similar levels of siderite are found in sulfate layers in other surveys, this could be a big missing piece to the puzzle of Mars' prior habitability. For all of human history, Mars has hung in the heavens as a tantalizing, red-hued mystery. Past civilizations associated the planet with the gods of war, and with the advent of telescopes in the 19th century, some even came to believe that the Red Planet was criss-crossed with artificial canals. Today—even though we know more about our celestial neighbor than at any point in history—many, many mysteries remain. One of the big remaining conundrums is what exactly happened in Mars' ancient past that transformed the world from a wet and warm one to the cold, dry orb we see today. Plenty of evidence indicates that water once flowed on the surface of Mars and that the planet once had a carbon dioxide-rich atmosphere, and this set of conditions should've interacted with Martian rocks to create carbonate minerals. However, even with the 18 orbital spacecraft and six rovers we've sent to Mars—each laden with various spectroscopic and scientific tools—scientists haven't found enough carbonate to support this theory. Now, in a new study, a team of more than 30 scientists analyzing data from NASA's Curiosity rover announce that they may have found the evidence they (and past teams just like them) have been looking for. The breakthrough comes from the discovery of siderite (an iron carbonate mineral) in the Martian topsoil that would've been 'invisible in previous orbital observations,' the scientists wrote in a paper published in the journal Science. '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,' Ben Tutolo, the lead author of the study and geochemist from the University of Calgary, said in a press statement. '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.' While climbing up a mountain in the Gale Crater, NASA's Curiosity rover—which originally arrived at the Red Planet back in 2011—analyzed three to four centimeters into the Martian soil by drilling into the subsurface and then dropping samples into its CheMin instrument. According to NASA, this instrument uses X-ray diffraction to analyze the chemical composition of the rocks and soil, and using this method, the rover discovered the iron carbonate siderate with sulfate-rich rocky layers. These highly water-soluble magnesium sulfate salts are what likely masked the siderite signature from orbital analysis. This evidence points to an imbalanced carbon cycle on Mars—the rocks and soil pulled more carbon dioxide out of the atmosphere than they replenished, causing the planet to lose its ability to support an atmosphere. Result? A cold, dry, and dead Mars. 'The broader implications are that 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,' Tutolo said in a press statement. '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?' It's taken humanity millennia of star-gazing and scientific inquiry to understand its red-hued neighbor, and now its puzzling planetary history is quickly coming into focus. You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
Yahoo
17-04-2025
- Science
- Yahoo
Curiosity Finds First In Situ Evidence of Carbon Cycle on Ancient Mars
A surprise discovery in Gale Crater is the component that was missing in the puzzle of Mars's climate history. There, embedded in the bedrock, the Curiosity rover has identified a mineral called siderite that can only have formed from the precipitation of carbon from the Martian atmosphere. In other words, billions of years ago, Mars had an active carbon cycle. It's the first in situ evidence of the carbon cycle on Mars, and it represents an important clue about whether or not the red planet could ever have supported life. "It tells us that the planet was habitable and that the models for habitability are correct," says geochemist Benjamin Tutolo of the University of Calgary in Canada. One of the biggest questions about ancient Mars involves its water. All evidence points to a planet that was rich in bodies of liquid water on its surface, with lakes and oceans that sloshed and lapped and crashed in waves upon shorelines. In order to be warm and stable enough for this liquid water, the atmosphere of Mars would have needed a significant amount of carbon dioxide, belched into the sky by the active volcanoes that were once rampant on the surface. Much of this carbon dioxide would have leaked out into space, but enough would have remained to warm Mars, and leave traces in the minerals on the surface. There's just one itty bitty problem. "Models predict that carbonate minerals should be widespread, but, to date, rover-based investigations and satellite-based orbital surveys of the Martian surface have found little evidence of their presence," Tutolo told ScienceAlert. The shock new discovery was found in data from 2022 and 2023, when the Curiosity rover, which has been beavering around Gale Crater for more than 10 years now, made X-ray diffraction analyses of minerals from different parts of the crater floor using its Chemistry and Mineralogy (CheMin) instrument. Tutolo and his colleagues carefully analyzed the measurements made by Curiosity, and found remarkably pure crystalline siderite in three of the four drill holes bored by Curiosity. This siderite, mostly composed of iron and carbon trioxide, with trace amounts of magnesium, stunned the researchers. "We were surprised to find carbonate minerals here because even the most detailed investigations of the orbital spectroscopy data acquired over these sedimentary rocks were unable to identify carbonate minerals," Tutolo said. "It turns out that the presence of other minerals – particularly highly water-soluble magnesium sulfate salts – likely masks the signature of carbonate minerals in the orbital data. Because similar rocks containing these salts have been identified globally, we infer that they, too, likely contain abundant carbonate minerals." So, not only does the discovery finally pony up the carbonate minerals scientists expected to find, it reveals why scientists have been unable to find them previously, and how to look for more of them across the red planet. The siderite identified in Curiosity data helps confirm and refine models of Mars's early warm period, more than 3.5 billion years ago. It confirms that carbon dioxide was abundant in the Martian atmosphere, and helped keep the planet warm enough for water; and that carbon was extracted from the atmosphere and trapped in minerals on the surface. But the formation of siderite, while good news for scientists studying Mars today, was part of the end of an era for Mars itself. "The important feature of the ancient Martian carbon cycle that we outline in this study is that it was imbalanced. In other words, substantially more CO2 seems to have been sequestered into the rocks than was subsequently released back into the atmosphere," Tutolo explained. "Because Mars is further away from the Sun than Earth, it needs substantially more CO2 in its atmosphere to maintain habitable conditions. The observation that geochemical processes were capturing and sequestering that CO2 suggests that this imbalanced carbon cycle may have challenged Mars's ability to remain habitable." These results have several implications. Now that scientists know that siderite is effectively invisible to orbital instruments, they can go back over previous data and look for strange signs of its presence they may have overlooked. In addition, rover-collected data may have more evidence of carbonate minerals. Now that researchers know mineral carbon sequestration took place on Mars, they can incorporate this information into models of the planet's climate history, and determine what role, if any, this capture played in the decline of Mars's habitability. These minerals, so common and unremarkable on Earth, have opened up a whole new way of understanding Mars. "I was trained as an aqueous geochemist and spent much of my career to date working on carbon sequestration as a solution for human-driven climate change. Working alongside the exceptionally talented and diverse expertise of the Mars Science Laboratory team, I was ultimately able to apply the knowledge I have gained from my climate change solutions work to interpret these mineralogical observations," Tutolo said. "Frankly, if you told me about all of this when I was 15, I never would have believed it!" The findings have been published in Science Advances. There's A Sky Full of Meteors in April! Here's What's on This Easter Weekend Meet Zhúlóng, The Milky Way 'Twin' That Shakes Up Our Cosmic Timeline New Form of Dark Matter May Explain Milky Way's Core Mysteries
