Helike also known as , is a moon

Natural satellite

A natural satellite or moon is a celestial body that orbits a planet or smaller body, which is called its primary. The two terms are used synonymously for non-artificial satellites of planets, of dwarf planets, and of minor planets....

 of Jupiter

Jupiter

Jupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...

. It was discovered by a team of astronomers from the University of Hawaii

University of Hawaii

The University of Hawaii System, formally the University of Hawaii and popularly known as UH, is a public, co-educational college and university system that confers associate, bachelor, master, and doctoral degrees through three university campuses, seven community college campuses, an employment...

 led by Scott S. Sheppard

Scott S. Sheppard

Scott S. Sheppard is an astronomer in the Department of Terrestrial Magnetism at the Carnegie Institution for Science. Starting as a graduate student at the Institute for Astronomy at the University of Hawaii, he was credited with the discovery of many small moons of Jupiter, Saturn, Uranus, and...

 in 2003, and given the temporary designation .

Helike is about 4 kilometres in diameter, and orbits Jupiter at an average distance of 20,540 Mm in 601.402 days, at an inclination

Inclination

Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...

 of 155° to the ecliptic

Ecliptic

The ecliptic is the plane of the earth's orbit around the sun. In more accurate terms, it is the intersection of the celestial sphere with the ecliptic plane, which is the geometric plane containing the mean orbit of the Earth around the Sun...

 (156° to Jupiter's equator), in a retrograde

Retrograde motion

Retrograde motion is motion in the direction opposite to the movement of something else, and is the contrary of direct or prograde motion. This motion can be the orbit of one body about another body or about some other point, or the rotation of a single body about its axis, or other phenomena such...

 direction and with an eccentricity of 0.1375.

It was named in March 2005 after Helike

Helike (mythology)

In Greek mythology, Helike was one of the nymphs who nurtured Zeus in his infancy on Crete . Her name suggests that she was a "willow-nymph", just as there were oak-tree nymphs and ash-nymphs ....

, one of the nymphs that nurtured Zeus

Zeus

In the ancient Greek religion, Zeus was the "Father of Gods and men" who ruled the Olympians of Mount Olympus as a father ruled the family. He was the god of sky and thunder in Greek mythology. His Roman counterpart is Jupiter and his Etruscan counterpart is Tinia.Zeus was the child of Cronus...

 (Jupiter) in his infancy on Crete

Crete

Crete is the largest and most populous of the Greek islands, the fifth largest island in the Mediterranean Sea, and one of the thirteen administrative regions of Greece. It forms a significant part of the economy and cultural heritage of Greece while retaining its own local cultural traits...

.

Helike belongs to the Ananke group

Ananke group

The Ananke group is a group of retrograde irregular satellites of Jupiter that follow similar orbits to Ananke and are thought to have a common origin....

, retrograde irregular moons which orbit Jupiter between 19.3 and 22.7 Gm, at inclinations of roughly 150°.