NASA's Curiosity Rover has discovered long carbon chains on Mars. On Earth, molecules like these are overwhelmingly produced by biological processes.

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.

Billions of years ago, Mars was warm, wet, and capable of sustaining liquid water on its surface. Scientists have long believed the Red Planet once had a dense atmosphere rich in carbon dioxide (CO₂),