Europa is the sixth closest moon of the planet Jupiter, and the smallest of its four Galilean satellites, but still one of the largest moons in the Solar System. Europa has emerged as one of the top locations in the Solar System in terms of potential habitability and the possibility of hosting extraterrestrial life. Life could exist in its under-ice ocean, perhaps subsisting in an environment similar to Earth’s deep-ocean hydrothermal vents. A new paper led by a NASA researcher shows that hydrogen peroxide is abundant across much of the surface of Jupiter’s moon Europa. The authors argue that if the peroxide on the surface of Europa mixes into the ocean below, it could be an important energy supply for simple forms of life, if life were to exist there. The paper was published online recently in the Astrophysical Journal Letters.