Meteorite may explain ‘how Mars turned to stone’ BBC

A meteorite reveals clues to how Mars lost its thick, carbon dioxide-rich atmosphere and became a cold, rocky desert, researchers say.
They say the Lafayette meteorite shows signs of carbonation – where minerals absorb CO2 in a reaction with water.
Mars lost its protective blanket about 4 billion years ago, perhaps because of the loss of its magnetic field, space impacts, or chemical processes.
Carbonation may be the key factor, they write in Nature Communications.