An Etymological Dictionary of Astronomy and Astrophysics

A small satellite of → Jupiter, ninth in order from the planet. It is about 8 km in diameter and orbits Jupiter at a mean distance of 7 500 000 km every 130 days. It was discovered in 1975, lost, and then rediscovered in 2000. Also known as Jupiter XVIII.

See also: Named after Themisto, daughter of the river god Inachus, who became the mother of Ister (the river Danube) by Zeus (Jupiter).