Europa (moon)

Europa is a <a href="/facts/Moons_of_Jupiter/Rq3GMt28">natural satellite (moon) of Jupiter</a>. Being observable from Earth with common binoculars it is one of the four <a href="/facts/Galilean_moons/aN6tLUFc">Galilean moons</a>. As such it is a <a href="/facts/Planetary-mass_moon/LSfyrXPB">planetary-mass moon</a>, the smallest and least massive orbiting Jupiter, and slightly smaller and less massive than <a href="/facts/Moon/zKHqEMPb">Earth's</a>. Europa is an icy moon, being of the three icy Galilean moons the closest orbiting Jupiter. As a result it is exhibiting a relatively young surface, driven by <a href="/facts/Tidal_heating/Ntl6sXJ0">tidal heating</a>.
Probably having an <a href="/facts/Iron%25E2%2580%2593nickel_alloy/dqyln0KA">iron–nickel</a> core, it consists mainly of <a href="/facts/Silicate/7NdthSRM">silicate</a> rock, with a water-ice shell. It has a very thin atmosphere, composed primarily of oxygen. Its geologically young white-<a href="/facts/Beige/y5N8TPz1">beige</a> surface is <a href="/facts/Glacial_striation/thwYzXMg">striated</a> by light <a href="/facts/Tan_(color)/mYwBAohf">tan</a> cracks and streaks, with very few impact craters. In addition to Earth-bound telescope observations, Europa has been examined by a succession of space-probe flybys, the first occurring in the early 1970s. In September 2022, the <a href="/facts/Juno_(spacecraft)/UzlYPApe">Juno</a> spacecraft flew within about 320 km (200 miles) of Europa for a more recent close-up view.
Europa has the smoothest surface of any known solid object in the Solar System. The apparent youth and smoothness of the surface is due to a <a href="/facts/Subsurface_ocean/8W8lYgjD">water ocean</a> beneath the surface, which could conceivably harbor <a href="/facts/Extraterrestrial_life/arxCPFTQ">extraterrestrial life</a>. The predominant model suggests that heat from <a href="/facts/Tidal_flexing/Ntl6sXJ0">tidal flexing</a> causes the ocean to remain liquid and drives ice movement similar to <a href="/facts/Plate_tectonics/RtRG5lY4">plate tectonics</a>, absorbing chemicals from the surface into the ocean below. <a href="/facts/Sea_salt/Gko2CC9k">Sea salt</a> from a subsurface ocean may be coating some geological features on Europa, suggesting that the ocean is interacting with the sea floor. This may be important in determining whether Europa could be habitable. In addition, the <a href="/facts/Hubble_Space_Telescope/NQeIf0vw">Hubble Space Telescope</a> detected <a href="/facts/Water_vapor/DX5IUFG0">water vapor plumes</a> similar to those observed on Saturn's moon <a href="/facts/Enceladus/DyWXz9jl">Enceladus</a>, which are thought to be caused by erupting <a href="/facts/Cryogeyser/cjXV4fCP">cryogeysers</a>. In May 2018, astronomers provided supporting evidence of water plume activity on Europa, based on an updated analysis of data obtained from the <a href="/facts/Galileo_(spacecraft)/H57agAgz">Galileo</a> space probe, which orbited Jupiter from 1995 to 2003. Such plume activity could help researchers in a search for life from the subsurface Europan ocean without having to land on the moon. In March 2024, astronomers reported that the surface of Europa may have much less <a href="/facts/Oxygen/acyn6o8r">oxygen</a> than previously inferred.
Europa was discovered independently by <a href="/facts/Simon_Marius/yb54huCF">Simon Marius</a> and <a href="/facts/Galileo_Galilei/98VT2z3v">Galileo Galilei</a>. It was named (by Marius) after <a href="/facts/Europa_(mythology)/G4AqvDrf">Europa</a>, the <a href="/facts/Phoenicia/6GXLneNU">Phoenician</a> mother of King <a href="/facts/Minos/NKe0GPPB">Minos</a> of <a href="/facts/Crete/VSqxTU9u">Crete</a> and lover of <a href="/facts/Zeus/9wTwkEDt">Zeus</a> (the Greek equivalent of the Roman god <a href="/facts/Jupiter_(mythology)/JPetM2m9">Jupiter</a>).
The Galileo mission, launched in 1989, provides the bulk of current data on Europa. No spacecraft has yet landed on Europa, although there have been several proposed exploration missions. The <a href="/facts/European_Space_Agency/L8YRNV0C">European Space Agency</a>'s <a href="/facts/Jupiter_Icy_Moons_Explorer/XcRkV5uS">Jupiter Icy Moons Explorer</a> (JUICE) is a mission to <a href="/facts/Ganymede_(moon)/AmKsF10c">Ganymede</a> launched on 14 April 2023, that will include two flybys of Europa. NASA's <a href="/facts/Europa_Clipper/LuaX203A">Europa Clipper</a> was launched on 14 October 2024.

Europa (moon) open-in-new

Europa (moon)