White rocks on Mars suggest ancient rainfall, hinting at a wetter past

White rocks on Mars suggest millions of years of ancient rainfall, challenging current understanding of the planet's past. These aluminum-rich kaolinite clays typically form on Earth only after prolonged exposure to heavy rainfall in warm, humid conditions, indicating Mars may have once had abundant water. The scattered rocks' origin remains a mystery, possibly linked to ancient floods, river transport, or asteroid impacts, offering clues to Mars' transition to a dry planet.