An asteroid collision
The arrival of Cyllene in the orbit of Jupiter is thought to have taken place when a much larger asteroid moving through space was pulled into Jupiter’s orbit. As this much larger asteroid moved through the orbit of Jupiter it is theorized a collision took place that shattered fragments of the much larger asteroid. Cyllene is thought to be one of these fragments of the larger asteroid that has taken up a position as one of the smaller moons of Jupiter.
Part of the Pasiphae group of asteroids
Cyllene is one of the moons of Jupiter known as the Pasiphae after the largest moon in its particular orbit. Astronomers believe the moon, Pasiphae was the original asteroid that moved into Jupiter’s orbit and caused the collision associated with the formation of the group of moons that all orbit in and around the same distance from the surface of Jupiter. The gray to light red colorings of the surface of Cyllene and the other moons in the Pasiphae group gives credence to the theory of a single asteroid crashing into the orbit of Jupiter.
Sinope raises questions about Cyllene
Cyllene is theorized to be one of the pieces of the asteroid Pasiphae that was captured by Jupiter’s gravity and formed a series of moons. Cyllene has been grouped with the largest fragment of the original asteroid, Pasiphae and with the smaller moon, Sinope. However, many researchers now question whether Sinope is one of the original parts of Pasiphae or whether it is an independent asteroid making its way into the same orbit as Cyllene and Pasiphae. If Sinope is an independent asteroid it means Cyllene is a much smaller part of the original asteroid than was originally thought.
Cyllene’s irregular shape
When a moon forms during the establishment of a planet, the common theory states the gravity and tidal pull of the planet forces the moon to take on a spherical shape. Cyllene has not taken on a spherical shape band that remains an irregular shape with a radius of around one kilometer and a diameter of just two kilometers.
The Orbit of Cyllene
Cyllene sits in an orbit around 23 million kilometers above the surface of Jupiter moving in a retrograde way. A retrograde orbit means the movement of Cyllene is in the opposite direction to the direction Jupiter naturally spins. The orbit of Cyllene is elliptical instead of circular and takes around 752 Earth days to complete a single orbit of the planet.
A team of astronomers and researchers from the University of Hawaii’s Manua Kea Observatory conducted a project to explore the rings of Jupiter for moons in the first few years of the 21st-century. Scott S. Shepherd and his team were responsible for discovering many moons, including Cyllene on February 9. 2003.
How Cyllene Got its Name?
The naming of an object in space must be done to coincide with the rules of the International Astronomy Union. Upon its discovery, Cyllene was classified with the name S2003/J13 or Jupiter XLVIII. Moons with a retrograde orbit are given names ending with the letter “e” to make them easily identifiable by astronomers with Jupiter’s moons traditionally given names associated with Greek Mythology. Cyllene was known as one of the daughters of Zeus in mythology and is usually described as a mountain nymph.