Curiosity Rover Discovers Siderite on Mars

• 19 Apr 2025

In April 2025, NASA’s Curiosity rover found siderite—an iron carbonate mineral—in Gale Crater on Mars, offering strong evidence of the planet’s once warm, wet, and potentially habitable environment.

Key Points

• Discovery of Siderite: The iron carbonate mineral was found in 2022–2023 drill samples from sedimentary rocks, suggesting Mars once had a thick CO₂-rich atmosphere.
• Clues to Ancient Climate: Siderite supports theories that greenhouse gases warmed ancient Mars enough to sustain lakes, rivers, and possibly life.
• Significant Carbon Storage: Up to 10.5% siderite by weight was detected, revealing that carbon dioxide may have become locked in Mars’ crust over time.
• Solving a Longstanding Mystery: This is a breakthrough in explaining the lack of widespread carbonate mineral detections on Mars despite climate models predicting their abundance.
• A Global Implication: Similar rocks exist across Mars, hinting at large-scale carbon sequestration and offering insight into the planet’s climate transformation.
• Imbalanced Carbon Cycle: Unlike Earth’s recycling via plate tectonics, ancient Mars likely trapped more CO₂ in rocks than it released—leading to a loss of habitability.