The Discovery of Hegemone
Discovering moons around Jupiter can be a difficult thing to do because of the nature of the planet that is a failed sun that did not fully form. Powerful telescopes and orbiters moving through space often struggle to focus on the moons around Jupiter because of the luminous nature of the planet. Hegemone was not discovered until 2003 when a team of astronomers led by Scott S. Shepherd at the University of Hawaii’s Mauna Kea Observatory.
The History of Hegemone
One of the major questions facing researchers looking at this and other moons of Jupiter is how did Jupiter gets so many moons. One answer is that different bands of moons were formed by asteroids moving into the orbit of the planet and becoming trapped. It is often theorized that Hegemone was formed by the arrival of a larger asteroid that collided with another object and created the moon.
Hegemone is a member of the Pasiphae Group
Hegemone is a member of the Pasiphae group of Jovian Satellites orbiting the planet a similar distance and speed from the surface of Jupiter. These satellites are thought to have been born from a single asteroid that remains in place as the Pasiphae moon that gives the band of objects its name. In recent years, the study of the moons of Jupiter in the Pasiphae band has shown varying colors of the objects with Hegemone’s fellow moons coming from different asteroids being dragged into the orbot of Jupiter.
A Retrograde Moon
The collision that gave birth to Hegemone and the other moons forming part of the Pasiphae band created a retrograde orbit for the moon and its fellow objects. A retrograde orbit means Hegemone moves in the opposite direction to the spinning of Jupiter as a whole. The orbit of Hegemone is also seen to be eccentric, which means it is not circular but moves in an oval around the equator of Jupiter.
Hegemone is an Irregular Shape
Because this moon is thought to have been born from a collision between an asteroid and another object in Jupiter’s orbit, the moon is not a traditional spherical shape. The diameter of the moon is around 1.8 miles with a radius of 0.9 miles.
The orbit of Hegemone around Jupiter takes it an average distance of 14.6 million miles from the surface of Jupiter throughout its orbit. The distance from Jupiter of the moon means it takes over two Earth years to complete a single orbit of the planet lasting around 740 days.
Where did Hegemone get its name?
The team that discovered Hegemone christened it with the scientific title, S/2003 J8 that was later changed to Jupiter XXXIX. In 2005, the decision was made to give the moon a name that would have to end in the letter “e” because all moons with a retrograde orbit have this classification in respect of the rules of the International Astronomical Union. Hegemone carries on the tradition of naming Jupiter’s moons from characters in Greek mythology. In this case, Hegemone was one of the daughters of the Greek God, Zeus and was known as the goddess of plants.