Galilean moon · moon of Jupiter
Europa
An ice-covered moon of Jupiter hiding a global salty ocean – one of the most promising places to look for life beyond Earth.
- Distance from Earth today
- 820.2 million km5.483 AU · light: 45 min 36 s
- Distance from the Sun today
- 795.1 million km5.315 AU
- As of
- 2 November 2026position from NASA/JPL orbital elements
Where it is today
Top view of the plane of Earth’s orbit, compressed distance scale. Open on the big map with the time slider →
Facts
- Diameter
- 3,122 km
- Mass
- 47,986 × 10¹⁸ kg
- Density
- 3,013 kg/m³
- Mean distance from the planet
- 671,100 km
- Orbital period
- 3.53 days
- Orbital eccentricity
- 0.0090
- Orbital inclination
- 0.5°
Source of the figures: JPL SSD – Planetary Satellites (public domain).
Discovery: 1610 – Galileo Galilei
Description
Europa, the smallest of the Galilean moons, has one of the smoothest surfaces in the Solar System: a bright shell of water ice criss-crossed by long cracks and ridges, with very few craters. Beneath that shell lies a global ocean of salty liquid water, kept from freezing by tidal heating; magnetic measurements by the Galileo spacecraft provided key evidence for it. Because that ocean is in contact with a rocky seafloor, Europa is considered one of the best places to search for habitable conditions beyond Earth. After the Voyagers, Galileo and Juno, NASA's Europa Clipper, launched in 2024, is on its way to study it in detail.