Thebe was discovered in 1980 by the Voyager science team from images taken by Voyager 1.
Thebe is one of the four known small moons that orbit closer to Jupiter than the four vastly larger Galilean moons. These eight are the only known "regular" Jovian satellites, which means that they orbit Jupiter in the same direction as the planet's rotation (prograde orbits), and that their orbits are almost circular and in the same plane as Jupiter's equator.
Thebe is the planet's seventh largest moon, with a mean radius of about 49 km. At a distance of about 138 thousand miles (222 thousand kilometers) from Jupiter, Thebe whips once around the planet in a little over 16 hours.
How Thebe Got Its Name
The satellite originally called S/1979 J2 was ultimately named "Thebe," a name associated with Jupiter — or his Greek equivalent, Zeus — in a variety of ways in different myths. In one, Thebe was a nymph who was a love of Zeus. In another, she was an Egyptian king's daughter and a love of Jupiter.
Along with its sister inner moon, Metis, Thebe was exempted from the International Astronomical Union's requirement that prograde satellites (not counting the Galilean moons) receive names ending in "a."