Autonoe (moon)

Autonoe , also known as Jupiter XXVIII, and previously as S/2001 J 1, is a small natural satellite or moon of Jupiter. Autonoe is one of the outermost irregular satellites of Jupiter, which orbit far from the planet on highly inclined and eccentric orbits. Autonoe was discovered by a team of astronomers from the University of Hawaiʻi led by Scott S. Sheppard in 2001, and was named after the Greek mythological figure Autonoe.

It orbits Jupiter in the retrograde direction—opposite to the direction of the planet's rotation—at an average distance of 23.7 million km (14.7 million mi). Autonoe shares similar orbital properties as Jupiter's larger irregular moon Pasiphae, which makes it a member of the Pasiphae group.The moons of the Pasiphae group are a group moons are believed to be fragments of an asteroid or trans-Neptunian object that was gravitationally captured by Jupiter and destroyed by a collision several billion years ago.

Due to different colour, Autonoe could be also an independent object, captured independently, unrelated to the collision and break-up at the origin of the group. Autonoe's physical properties are unknown, it estimated to be about 4 km in diameter and its surface is be probably dark and lightred in color.

Discovery and naming

Autonoe was discovered in Dezember 2001, along with ten other Jovian moons by a team of astronomers from the University of Hawaiʻi led by Scott S. Sheppard and given the temporary designation S/2001 J 1.

Autonoe was named in August 2003 after the Greek mythological figure Autonoe, conquest of Zeus (Jupiter), mother of the Charites (Graces), according to some authors.

Orbit

The satellite orbits Jupiter at a mean distance of 23.785.200 km and completes one orbit in 749,61 days.