Research from NASA's Curiosity rover has found evidence of a carbon cycle on ancient Mars, bringing scientists closer to an answer on whether the red planet was ever capable of supporting life.

Tutolo says scientists are ultimately trying to determine whether Mars was ever capable of supporting life—and the latest paper brings them closer to an answer.

“It tells us that the planet was habitable and that the models for habitability are correct,” he says.

"The broader implications are the planet was habitable up until this time, but then, as the CO2 that had been warming the planet started to precipitate as siderite, it likely impacted Mars’ ability to stay warm.