Elara (moon)
Encyclopedia
Elara is a prograde
irregular
satellite
of Jupiter
. It was discovered by Charles Dillon Perrine
at Lick Observatory
in 1905. It is the eighth largest moon of Jupiter and is named after the mother by Zeus
of the giant Tityus.
Elara did not receive its present name until 1975; before then, it was simply known as . It was sometimes called "Hera
" between 1955 and 1975.
Elara belongs to the Himalia group
, five moons orbiting between 11 and 13 Gm from Jupiter at an inclination of about 27.5°. Its orbital elements are as of January 2000. They are continuously changing due to solar
and planetary perturbations.
spacecraft to Pluto
captured Elara in several LORRI images from a distance of five million miles.
Prograde
Prograde can refer to:*Prograde or direct motion, in astronomy, a type of motion of astronomical bodies* Prograde metamorphism, in geology, describes mineral changes in rocks under increasing pressure and/or temperature conditions...
irregular
Irregular satellite
In astronomy, an irregular moon is a natural satellite following a distant, inclined, and often eccentric and retrograde orbit. They are believed to have been captured by their parent planet, unlike regular satellites, which form in situ....
satellite
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 Charles Dillon Perrine
Charles Dillon Perrine
Charles Dillon Perrine was an American astronomer living in Argentina.Born in Steubenville, Ohio, a son of Peter and Elizabeth McCauley Perrine, and a descendant of Daniel Perrin, "The Huguenot", he worked at Lick Observatory from 1893 to 1909 and then was director of the Argentine National...
at Lick Observatory
Lick Observatory
The Lick Observatory is an astronomical observatory, owned and operated by the University of California. It is situated on the summit of Mount Hamilton, in the Diablo Range just east of San Jose, California, USA...
in 1905. It is the eighth largest moon of Jupiter and is named after the mother by 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...
of the giant Tityus.
Elara did not receive its present name until 1975; before then, it was simply known as . It was sometimes called "Hera
Hera
Hera was the wife and one of three sisters of Zeus in the Olympian pantheon of Greek mythology and religion. Her chief function was as the goddess of women and marriage. Her counterpart in the religion of ancient Rome was Juno. The cow and the peacock were sacred to her...
" between 1955 and 1975.
Elara belongs to the Himalia group
Himalia group
The Himalia group is a group of prograde irregular satellites of Jupiter that follow similar orbits to Himalia and are thought to have a common origin.The known members of the group are :* Leda...
, five moons orbiting between 11 and 13 Gm from Jupiter at an inclination of about 27.5°. Its orbital elements are as of January 2000. They are continuously changing due to solar
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
and planetary perturbations.
New Horizons encounter
In February and March 2007, the New HorizonsNew Horizons
New Horizons is a NASA robotic spacecraft mission currently en route to the dwarf planet Pluto. It is expected to be the first spacecraft to fly by and study Pluto and its moons, Charon, Nix, Hydra and S/2011 P 1. Its estimated arrival date at the Pluto-Charon system is July 14th, 2015...
spacecraft to Pluto
Pluto
Pluto, formal designation 134340 Pluto, is the second-most-massive known dwarf planet in the Solar System and the tenth-most-massive body observed directly orbiting the Sun...
captured Elara in several LORRI images from a distance of five million miles.
External links
- Elara on 1998-08-15 03:21 UTC (Crédit : OHP/IMCCE/CNRS)
- SkyView 23 47 09 -02 40 46
- HORIZONS Web-Interface
- Elara Profile by NASA's Solar System Exploration
- David Jewitt pages
- Jupiter's Known Satellites (by Scott S. SheppardScott S. SheppardScott 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...
)