Finding extraterrestrial life in our solar system just got a huge boost. NASA’s Cassini space probe has detected molecular hydrogen in the plumes of saltwater that burst from the oceans buried beneath the icy surface of Saturn’s moon Enceladus. Scientists remain cautiously agnostic, but the discovery of key ingredients for life is a game changer. With subsurface oceans found beneath other moons in our solar system, most famously Jupiter’s frozen moon Europa, the chances of finding extraterrestrial life (at the bacterial level at least) is exciting. It also has implications for the possibility of alien life elsewhere in the galaxy. We’re only now able to detect atmospheres on planets orbiting distant stars — what about their moons?