Afterward, as Curiosity drove away from Yellowknife Bay, onboard equipment ground the rock samples to a fine dust and chemically analyzed their content in extreme detail to learn as much as possible about the site. Today, the results of that analysis were finally published in a series of articles in Science, and it’s safe to say that the scientists probably don’t regret making that brief detour. Yellowknife Bay, they discovered, was likely once home to a calm freshwater lake that lasted for tens of thousands of years, and theoretically had all the right ingredients to sustain microbial life.

“This is a huge positive step for the exploration of Mars,” said Sanjeev Gupta, an Earth scientist at Imperial College London and a member of the Curiosity team, in a press statement on the discovery. “It is exciting to think that billions of years ago, ancient microbial life may have existed in the lake’s calm waters, converting a rich array of elements into energy.”