Elara is a
prograde irregular satellite
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioiso ...
of
Jupiter
Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other planets in the Solar System combined, but slightly less than one-thousandt ...
. It was discovered by
Charles Dillon Perrine
Charles Dillon Perrine (July 28, 1867June 21, 1951) was an American astronomer at the Lick Observatory in California (1893-1909) who moved to Cordoba, Argentina to accept the position of Director of the Argentine National Observatory (1909-1936 ...
at
Lick Observatory in 1905 in photographs taken with the 36" Crossley reflecting telescope which he had recently rebuilt.
It is the eighth-largest moon of Jupiter and is named after
Elara, one of
Zeus
Zeus or , , ; grc, Δῐός, ''Diós'', label=genitive Boeotian Aeolic and Laconian grc-dor, Δεύς, Deús ; grc, Δέος, ''Déos'', label=genitive el, Δίας, ''Días'' () is the sky and thunder god in ancient Greek religion, ...
's lovers and the mother of the giant
Tityos
Tityos or Tityus (Ancient Greece, Ancient Greek: Τιτυός) was a Giant (mythology), giant from Greek mythology.
Family
Tityos was the son of Elara (mythology), Elara; his father was Zeus. He had a daughter named Europa (Greek myth), Europa ...
.
Elara did not receive its present name until 1975; before then, it was simply known as . It was sometimes called "
Hera
In ancient Greek religion, Hera (; grc-gre, Ἥρα, Hḗrā; grc, Ἥρη, Hḗrē, label=none in Ionic and Homeric Greek) is the goddess of marriage, women and family, and the protector of women during childbirth. In Greek mythology, she ...
"
between 1955 and 1975. It has a mean radius of just , thus it is 2% of the size of
Europa. However, it is half the size of
Himalia, so it is the second-biggest moon in the
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.Scott S. Sheppard, David C. Jewitt
''An abundant population of small irregular satellites arou ...
. It might be a captured type C or D asteroid, for it reflects very little light.
Elara belongs to the Himalia group, moons orbiting between 11 and 13
gigametres 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.
Discovery
Elara was discovered by
Charles Dillon Perrine
Charles Dillon Perrine (July 28, 1867June 21, 1951) was an American astronomer at the Lick Observatory in California (1893-1909) who moved to Cordoba, Argentina to accept the position of Director of the Argentine National Observatory (1909-1936 ...
of the Lick Observatory on January 6, 1905, the day after the discovery of
Himalia, also by Perrine, was announced. However, poor weather conditions delayed the confirmation of the discovery till the 21st of February.
New Horizons encounter
In February and March 2007, the ''
New Horizons
''New Horizons'' is an interplanetary space probe that was launched as a part of NASA's New Frontiers program. Engineered by the Johns Hopkins University Applied Physics Laboratory (APL) and the Southwest Research Institute (SwRI), with a t ...
'' spacecraft to
Pluto
Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Sun. It is the largest k ...
captured Elara in several
LORRI Lorri may refer to:
Acronym
* LORRI, the Long Range Reconnaissance Imager, a camera on board the ''New Horizons'' spacecraft
Given name
* Lorri Bagley, an American actress and model
* Lorri Jean, a leader in the gay, lesbian, bisexual and trans ...
images from a distance of five million miles.
See also
*
Jupiter's moons in fiction
Jupiter, the largest planet in the Solar System, has appeared in works of fiction across several centuries. The way the planet has been depicted has evolved as more has become known about its composition; it was initially portrayed as being entir ...
References
External links
Elara on 1998-08-15 03:21 UTCCrédit: OHP/
IMCCE/
CNRS
The French National Centre for Scientific Research (french: link=no, Centre national de la recherche scientifique, CNRS) is the French state research organisation and is the largest fundamental science agency in Europe.
In 2016, it employed 31,63 ...
)
SkyView 23 47 09 -02 40 46HORIZONS Web-Interface JPL
Elara: Overviewb
NASA's Solar System Exploration(Himalia & Elara: Remanzacco Observatory: November 23, 2012)
{{DEFAULTSORT:Elara (Moon)
Himalia group
Moons of Jupiter
Irregular satellites
19050105
Discoveries by Charles D. Perrine
Moons with a prograde orbit