Scientists using NASA’s Curiosity rover have found siderite—a type of iron carbonate—in sulfate-rich rocks in Gale Crater, solving a mystery about Mars’ missing carbonates. The discovery suggests that the planet once had conditions suitable for liquid water and provides clues about its ancient atmosphere.
Data from three drill sites show the presence of siderite within rock layers on Mount Sharp, located in Gale Crater. This finding contradicts previous satellite data and indicates that more carbon may be hidden beneath the Martian surface or lost to space.
The discovery is a significant breakthrough in understanding Mars’ geologic and atmospheric evolution. Scientists used X-ray diffraction to analyze the mineral structure of the rocks, revealing that the carbonate minerals formed around 3.5 billion years ago.
If other sulfate-rich layers across Mars also contain carbonates, it would suggest a fraction of the stored carbon dioxide needed for an ancient atmosphere to create conditions warm enough to support liquid water. The rest could be hidden in other deposits or lost to space over time.
Future missions and analyses of other sulfate-rich areas on Mars will help confirm these findings and shed more light on the planet’s early history and its transformation as its atmosphere was lost.
Source: https://scitechdaily.com/mars-kept-a-secret-for-3-5-billion-years-nasas-curiosity-rover-finally-dug-it-up