Mars has long been considered a lifeless red desert, but new research suggests that it may have had a warm and habitable climate billions of years ago. The discovery was made possible by a study of rock samples collected by the Curiosity rover in Gale Crater, which is home to the tallest sediment stack on Mars.
According to researchers, for Mars to support liquid water and a warm surface temperature, there must have been significant amounts of carbon dioxide in its atmosphere. However, satellite observations have shown much less carbon in Martian soil than predicted climate models suggested.
Leading researcher Benjamin Tutolo attributes this discrepancy to incorrect climate models or the presence of hidden carbon reserves on Mars. To resolve this mystery, scientists turned to on-site analysis of Martian rocks using instruments carried by the Curiosity rover. These findings could provide crucial insights into Mars’ past and its potential habitability.
Source: https://arstechnica.com/science/2025/04/rover-finds-hints-of-an-ancient-martian-carbon-cycle