Europa is one of the largest of Jupiter’s more than 90 moons. It's the sixth-closest moon to the planet. Europa and Jupiter’s three other largest moons – Io, Ganymede, and Callisto – were the first moons discovered beyond Earth. They are called the Galilean moons after Italian astronomer Galileo Galilei, who first observed them with a homemade telescope in January 1610.
Europa is primarily made of silicate rock and has a water-ice crust and probably an iron-nickel core. It has a very thin atmosphere, composed primarily of oxygen. Cracks and streaks striate its surface, but craters are relatively few. Scientists are almost certain that hidden beneath the icy surface of Europa is a saltwater ocean with about twice as much water as Earth’s global ocean.
Europa may be one of the most promising places in our solar system to find present-day environments suitable for some form of life beyond Earth. Scientists believe a saltwater ocean lies beneath its icy shell, holding twice as much water as Earth's global ocean, and possibly the chemical elements that are key ingredients to life. NASA is sending its Europa Clipper spacecraft in 2024 to investigate whether Europa has the capability to support life, and is scheduled to enter orbit and begin its search in 2030.
- Europa has been featured in short stories, comics, and novels, with perhaps the best known being the Arthur C. Clarke novel “2010: Odyssey Two,” which was also adapted for film.
- In “The Expanse” television series (2015–2022), people live and grow food on Europa.
- At least two “Star Trek” federation starships were named for Europa, and in “Star Trek: Picard” a mission to Europa helped save Earth.
- Europa was the setting for the 2013 film “Europa Report,” and it was featured in an episode of the animated television show “Futurama.”
- The moon has also been the setting or subject of several video games, including “Call of Duty: Infinite Warfare” and “Galaga: Destination Earth.”