Gizmodo:

No, NASA hasn’t discovered life on Mars yet—but a new result makes it seem like maybe, at some point in the planet’s history, the conditions were ripe for some extraterrestrial beings. Maybe.

The scientists behind experiments conducted by the Curiosity rover are today reporting two results that make the Red Planet’s story even more interesting. One group found carbon-containing organic matter in 3.5-billion-year-old rock. Another noticed the methane levels around Curiosity varied by the season. Combined, these results present tantalizing hints of a potentially habitable Martian past.

This is so cool.