Elara (moon)

Elara
	Elara near the glare of bright Jupiter
Discovery
Discovered by	C. D. Perrine
Discovery date	January 5, 1905
Orbital characteristics
Mean orbit radius	11,740,000 km (0.07810 AU)
Eccentricity	0.22
Orbital period	259.64 d (0.708 a)
Average orbital speed	3.27 km/s
Inclination	26.63° (to the ecliptic); 30.66° (to Jupiter's equator)
Satellite of	Jupiter
Physical characteristics
Mean radius	43 km
Surface area	~23,200 km2
Volume	~333,000 km3
Mass	8.7×1017 kg
Mean density	2.6 g/cm3 (assumed)
Surface gravity	~0.031 m/s2 (0.003 g)
Escape velocity	~0.052 km/s
Sidereal rotation period	~0.5 d (12 h)
Albedo	0.04 (assumed)
Temperature	~124 K
Apparent magnitude	16.3

Elara is a non-spherical moon of Jupiter. It was found by Charles Dillon Perrine at Lick Observatory in 1905^[1]^[2] and is named after the mother by Zeus of the giant Tityus.^[5]

Elara did not get its present name until 1975; before then, it was simply known as Jupiter VII. It was sometimes called "Hera"^[6] between 1955 and 1975.

Elara belongs to the Himalia group, five moons orbiting between 11,000,000 and 13,000,000 km from Jupiter at an inclination of about 27.5°.^[3] Its orbital elements are as of January 2000. They are changing a lot due to Solar and planetary perturbations.

New Horizons encounter

In February and March 2007, the New Horizons spacecraft to Pluto made a number of pictures of Elara, culminating in photos from a distance of five million miles.

References

↑ ^1.0 ^1.1 Perrine, C. D. (1905-02-27). "Satellites of Jupiter". Harvard College Observatory Bulletin. 178.
↑ ^2.0 ^2.1 Perrine, C. D. (1905). "The Seventh Satellite of Jupiter". Publications of the Astronomical Society of the Pacific. 17 (101): 62–63. Bibcode:1905PASP...17...56.. doi:10.1086/121624. JSTOR 40691209. S2CID 250794880.
↑ ^3.0 ^3.1 ^3.2 ^3.3 ^3.4 ^3.5 Jacobson, R. A. (2000). "The orbits of outer Jovian satellites" (PDF). Astronomical Journal. 120 (5): 2679–2686. Bibcode:2000AJ....120.2679J. doi:10.1086/316817. S2CID 120372170.
↑ ^4.0 ^4.1 ^4.2 ^4.3 "Planetary Satellite Physical Parameters". JPL (Solar System Dynamics). Retrieved 2009-08-10.
↑ Marsden, B. G. (7 October 1974). "Satellites of Jupiter". IAUC Circular. 2846.
↑ Payne-Gaposchkin, Cecilia; Katherine Haramundanis (1970). Introduction to Astronomy. Englewood Cliffs, N.J.: Prentice-Hall. ISBN 0-134-78107-4.

Other websites

Elara Profile Archived 2007-11-09 at the Wayback Machine by NASA's Solar System Exploration
David Jewitt pages
Scott Sheppard pages

[Harvard_1905-1] 1.0 ^1.1 Perrine, C. D. (1905-02-27). "Satellites of Jupiter". Harvard College Observatory Bulletin. 178.

[Perrine_1905-2] 2.0 ^2.1 Perrine, C. D. (1905). "The Seventh Satellite of Jupiter". Publications of the Astronomical Society of the Pacific. 17 (101): 62–63. Bibcode:1905PASP...17...56.. doi:10.1086/121624. JSTOR 40691209. S2CID 250794880.

[Jacobson_2000-3] 3.0 ^3.1 ^3.2 ^3.3 ^3.4 ^3.5 Jacobson, R. A. (2000). "The orbits of outer Jovian satellites" (PDF). Astronomical Journal. 120 (5): 2679–2686. Bibcode:2000AJ....120.2679J. doi:10.1086/316817. S2CID 120372170.

[jplssd-4] 4.0 ^4.1 ^4.2 ^4.3 "Planetary Satellite Physical Parameters". JPL (Solar System Dynamics). Retrieved 2009-08-10.

[IAUC_2846-5] Marsden, B. G. (7 October 1974). "Satellites of Jupiter". IAUC Circular. 2846.

[Gaposchkin-6] Payne-Gaposchkin, Cecilia; Katherine Haramundanis (1970). Introduction to Astronomy. Englewood Cliffs, N.J.: Prentice-Hall. ISBN 0-134-78107-4.

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v t e Moons of Jupiter
Listed in increasing approximate distance from Jupiter
Inner moons (4)	Metis Adrastea Amalthea Thebe
Galilean moons (4)	Io Europa Ganymede Callisto
Themisto group (1)	Themisto
Himalia group (9)	Leda Ersa S/2018 J 2 Himalia Pandia Lysithea Elara S/2011 J 3 Dia
Carpo group (2)	S/2018 J 4 Carpo
Valetudo group (1)	Valetudo
Ananke group (26)	Euporie Jupiter LV Eupheme S/2021 J 3 Jupiter LII Jupiter LIV Mneme Euanthe S/2003 J 16 Harpalyke Orthosie S/2022 J 3 Helike S/2021 J 2 Praxidike Jupiter LXIV S/2021 J 1 S/2003 J 12 Jupiter LXVIII Thelxinoe Thyone S/2003 J 2 Ananke Iocaste Hermippe Jupiter LXX
Carme group (30)	S/2022 J 1 S/2022 J 2 S/2016 J 3 Pasithee Jupiter LXIX S/2021 J 6 S/2003 J 24 Chaldene Jupiter LXIII Isonoe S/2021 J 4 Kallichore Erinome Kale Eirene Aitne Eukelade Arche Taygete Jupiter LXXII Carme Herse Jupiter LXI Jupiter LI S/2003 J 9 Jupiter LXVI Kalyke S/2018 J 3 S/2021 J 5 S/2003 J 10
Pasiphaë group (18)	Philophrosyne Eurydome Jupiter LVI S/2003 J 4 S/2016 J 4 Jupiter LXVII Hegemone Pasiphaë Sponde Megaclite Cyllene Sinope Jupiter LIX Aoede Autonoe Callirrhoe S/2003 J 23 Kore
Related page	Rings of Jupiter
Category