Helike (moon)

Helike is a retrograde irregular satellite of Jupiter. It was discovered by a team of astronomers from the University of Hawaii led by Scott S. Sheppard in 2003, and received the provisional designation S/2003 J 6.

Helike is approximately 4 kilometers in diameter and orbits Jupiter at an average distance of 20.542 million kilometers in 601.402 days, at an inclination of 154.8° to the ecliptic (156° to Jupiter's equator) and with an eccentricity of 0.1375.

It belongs to the Ananke group, a family of retrograde irregular satellites that orbit Jupiter at similar distances and inclinations. This group is believed to have originated from the breakup of a larger asteroid or comet captured by Jupiter's gravity.

The moon was named after Helike, one of the nymphs who nursed Zeus (the Greek equivalent of Jupiter) in his infancy, according to Greek mythology. The official naming was announced on August 30, 2003.