jovian satellites See ADRASTEA (JUPITER XV); AMALTHEA (JUPITER V); ANANKE (JUPITER XII); CALLISTO (JUPITER IV); CARME (JUPITER XI); ELARA (JUPITER VII); EUROPA (JUPITER II); GANYMEDE (JUPITER III); HIMALIA (JUPITER VI); IO (JUPITER I); LEDA (JUPITER XIII); LYSITHEA (JUPITER X); METIS (JUPITER XVI); PASIPHAE (JUPITER VIII); SINOPE (JUPITER IX); and THEBE (JUPITER XIV).

Galilean satellites The four classical satellites Io, Europa, Ganymede, and Callisto (in order outwards from Jupiter) which were discovered in 1610 by Galileo. The observation that they orbited a body other than the Earth was fatal to the Ptolemaic cosmology. Ganymede (radius 2638 km) is the largest satellite in the solar system, larger than both Mercury and Pluto. Europa (radius 1536 km), the smallest of the four, is a little smaller than the Moon (radius 1738 km). They occupy equatorial orbits. There is a regular decrease in density from Io (3550 kg/m³) to Callisto (1830 kg/m³), Callisto preserving one of the most heavily cratered surfaces of any satellite.

Galilean satellites Four chief satellites of Jupiter: Ganymede, Callisto, Io and Europa, named after Galileo.