While slowly climbing the slopes of Mount Sharp — a towering peak inside Mars' Gale Crater — NASA's Curiosity rover made a remarkable discovery: large deposits of carbon locked away in carbonate minerals. That may sound a little dry at first, but in reality this find could be a major piece of the puzzle in our search for ancient life on the Red Planet.

Carbonate minerals form when carbon dioxide interacts with water and rock, making them an important marker of past environmental conditions. Scientists have spotted these minerals before on Mars — by rovers on the ground, orbiters above, and even in Martian meteorites that fell to Earth — but Curiosity's latest data adds exciting new details.

"It tells us that the planet was habitable and that the models for habitability are correct," said the study's lead author, Ben Tutolo, associate professor with the Department of Earth, Energy and Environment in the Faculty of Science at the University of Calgary, in a statement.