Cyllenes

Cyllenes refers to a group of small, rocky moons orbiting the planet Jupiter. They are classified as irregular moons, meaning their orbits are highly elliptical and inclined compared to the regular, nearly circular orbits of Jupiter's larger satellites. The Cyllene group is named after the outermost known member, Cyllene.

These moons are believed to be captured asteroids that strayed too close to Jupiter and were caught in its gravitational pull. Their small size and irregular orbits make them difficult to observe and study. Due to their distant and eccentric paths, they spend a significant portion of their orbits far from Jupiter, making sustained observation challenging.

The Cyllene group is part of a larger collection of Jovian moons that orbit in a retrograde direction, meaning they travel in the opposite direction of Jupiter's rotation. This characteristic further supports the theory of their capture origin. Like many irregular moons, the Cyllene satellites are thought to be relatively ancient, having survived numerous close encounters with Jupiter and other celestial bodies over billions of years. Their composition is likely similar to that of C-type asteroids, which are rich in carbon.