In those drill sites, Curiosity detected deposits containing an iron carbonate material called siderite. According to Ben Tutolo, a University of Calgary associate professor of Earth, Energy, and Environment Studies as well as a NASA Mars Science Laboratory Curiosity Rover team, the data marks a major moment in the search for extraterrestrial life.

A surprise discovery in Gale Crater is the component that was missing in the puzzle of Mars's climate history. There, embedded in the bedrock, the Curiosity rover has identified a mineral called siderite that can only have formed from the precipitation of carbon from the Martian atmosphere.