Gas-solid carbonation as a possible source of carbonates in cold planetary environments

► We report for the first time that CaCO3 could be formed at a negative temperature. ► Results suggest that gas-solid carbonation process could be currently active on Mars. ► A setup of an infrared microscope coupled to a cryogenic reaction cell has been used. ► We have fitted experimental data using a kinetic double-pseudo-second-order model. ► Gas-solid carbonation process could have implications in cold environments.