Adrastea, a moon of Jupiter
Adrastea from Galileo orbiter, taken in 1996 or 1997. Image credit: NASA/JPL/Cornell University
80,157 miles
10 miles
Adrastea is the second closest moon to Jupiter. It is one of Jupiter's four inner moons. These are a group of small moons that orbit in between Jupiter and its largest moons, the Galilean moons. Jupiter's inner moons are Metis, Adrastea, Amalthea and Thebe.
Also orbiting Jupiter are faint rings. Adrastea is situated very close to Jupiter's main ring, orbiting on its outer edge. In fact it is thought that most of the material in Jupiter's main ring comes from Adrastea from when objects like meteorites smash into its surface and blast rocks and dust from it. Adrastea also seems to hold Jupiter's main ring in place, assisted by its neighbouring moon Metis which orbits on the opposite side of the ring. These two moons are called shepherd moons.
In Greek mythology, Adrastea was the daughter of King Melisseus of Crete. When Rhea gave birth to Zeus, she requested that Adrastea and Ida bring him up in secret to protect him from his father Cronus. It is said that she gave him a toy globe to play with. They sisters were assisted in their babysitting role by a group of dancers called the Curetes, who drowned out Zeus' cries by banging their swords on their shields.
Adrastea also means "inescapable" which might be because Adrastea was thought to be the goddess of "inevitable fate" and had something to do with people always having to face the consequences of their actions.