Image of Thebe taken by Galileo spacecraft. Image Credit: NASA
Thebe is a moon orbiting Jupiter and is the fourth closest moon to the planet. It was formerly known as S/1979 J 2 and also Jupiter XIV. Its orbit has a semi-major axis of 221,900 km, an eccentricity of 0.018, and an inclination of 1.08 degrees to the equator of Jupiter. It was fairly recently discovered, as moons go, having been discovered by Stephen Synnott while he was studying images returned by the Voyager1 probe. Those images were taken on March 5, 1979.
Thebe lends its name and surface material to the Thebe Gossamer Ring. That ring is formed from dust ejected from the moon’s surface after it is impacted by meteroites. Thebe, the second largest of the inner Jovian satellites, is one of only eight Jovian moons that orbit in a prograde motion. The moon is irregularly shaped and reddish in color. Many scientist believe that it consists of porous water ice and unknown amounts of other materials. It features a number of craters and mountains on its surface. The largest crater has an approximate diameter of 40 km.
Despite having been imaged by Voyager 1 and Voyager 2, very little was known about the moon until the arrival of the Galileo spacecraft in 1995, which imaged nearly the entire surface of the moon and returned clues to its composition. The irregularly shaped moon has an approximate size of 116×98×84 km. The best estimate of its mass is roughly 4.3 x 1017kg. Thebe rotates synchronously with its orbital motion, always keeping the same side toward the planet. More specifically, the long axis always points to Jupiter at all times.
We have written many articles about Thebe for Universe Today. Here’s an article about Jupiter’s moons, and here are some interesting facts about Jupiter.
If you’d like more info on Thebe, check out these articles:
Solar System Exploration Guide: Thebe
Thebe (moon)
We’ve also recorded an episode of Astronomy Cast just about Jupiter. Listen here, Episode 56: Jupiter.
Source: NASA
Comments on this entry are closed.