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 ...

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-thousand ...

. 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 ...

Lick Observatory The Lick Observatory is an astronomical observatory owned and operated by the University of California. It is on the summit of Mount Hamilton, in the Diablo Range just east of San Jose, California, United States. The observatory is managed by t ...

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 relig ...

's lovers and the mother of the giant

Tityos Tityos or Tityus ( Ancient Greek: Τιτυός) was a giant from Greek mythology. Family Tityos was the son of Elara; his father was Zeus. He had a daughter named Europa who coupled with Poseidon and gave birth to Euphemus, one of the Argo ...

. 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 Europa may refer to: Places * Europe * Europa (Roman province), a province within the Diocese of Thrace * Europa (Seville Metro), Seville, Spain; a station on the Seville Metro * Europa City, Paris, France; a planned development * Europa Clif ...

. However, it is half the size of Himalia, so it is the second-biggest moon in the Himalia group. 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

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 ...

'' spacecraft to

Pluto Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the S ...

captured Elara in several LORRI images from a distance of five million miles.

References

External links

Elara on 1998-08-15 03:21 UTC
Crédit: 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 46

HORIZONS Web-Interface
JPL
Elara: Overview
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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

Discovery

New Horizons encounter

See also

References

External links