Who discovered Metis and when?
Metis was discovered in 1979 by Stephen P. Synnott using images taken by the Voyager 1 spacecraft. It received a provisional designation at the time and was not officially named until 1983.
Questions about Metis (moon)
Short answers, pulled from the story.
Why is Metis named after a figure from Greek mythology?
In Greek mythology, Metis was a Titaness and the first wife of Zeus, who served as the Greek prototype for the Roman god Jupiter. She was also the mother of Athena. The name connects the moon to the same mythological tradition as the planet it orbits.
How long does it take Metis to orbit Jupiter?
Metis completes one orbit of Jupiter in approximately 7 hours. That is faster than Jupiter itself rotates, making Metis one of only two known moons to orbit the planet in less time than a Jovian day. The other is Adrastea.
Why is one side of Metis brighter than the other?
The leading hemisphere of Metis is about 1.3 times brighter than the trailing hemisphere. Scientists believe this is because the leading face experiences more frequent and higher-velocity meteorite impacts, which excavate bright material, thought to be ice, from the interior.
Is Metis in danger of being torn apart by Jupiter's gravity?
Metis may orbit within its fluid Roche limit, the distance inside which tidal forces could disintegrate a body held together only by self-gravity. Because it has not broken apart, scientists conclude it must lie outside its rigid Roche limit, meaning its internal solid strength is holding it together.
What role does Metis play in Jupiter's ring system?
Metis is a major contributor of dust to Jupiter's main ring. Meteorite impacts on its surface eject material that easily escapes into space, because the moon's low density means its gravitational sphere of influence barely extends beyond its surface. That escaped debris feeds the ring. Metis orbits within a roughly 500-kilometer-wide gap in the ring, though the exact connection between the moon and the gap remains unexplained.