Moon

Europa

An icy moon of Jupiter with a global salty ocean beneath its surface.

NASA, ESA, CSA, STScI; J. DePasquale, A. Koekemoer, A. Pagan (STScI) (CC BY 4.0)

Under a shell of cracked ice lies a salty ocean: one of the best places to look for life beyond Earth.

Jupiter with its moon Europa beside it. — Jupiter and its moon Europa, photographed by the Hubble Space Telescope in 2020. Credit: NASA, ESA, A. Simon (Goddard Space Flight Center), and M. H. Wong (University of California, Berkeley) and the OPAL team, CC BY 4.0

Europa’s surface is smooth water ice crossed by long cracks and ridges. Measurements of its magnetic field indicate a salty liquid water ocean beneath the ice, making it one of the most promising places to look for life beyond Earth.

NASA’s Europa Clipper mission, launched in 2024, will study it in detail.

Data sources

JPL SSD: Planetary Satellite Physical Parameters

Key facts
Diameter	3,122 km	[1]
Mass	4.799 × 10²² kg	[1]
Density	3.013 g/cm³	[1]
Surface gravity	1.31 m/s²	Derived from the dataset
Escape speed	2.03 km/s	Derived from the dataset
Rotation (sidereal)	3.53 days	[2]
Orbital period	3.53 days	[2]
Distance from Jupiter	671,100 km	[2]
always shows the same face to Jupiter

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