Elara

Discovery
Discovered by	C. D. Perrine
Discovered on	January 2 1905
Orbital characteristics
Mean radius	11,716,000 km
Eccentricity	0.155-0.272
Orbital period	259.1d
Inclination	1.4-46.7°
Is a satellite of	Jupiter
Physical characteristics
Mean diameter	86 km
Surface area	km2
Mass	8.7×1018 kg
Mean density	2.6 g/cm3
Surface gravity	0.031 m/s2
Rotation period	~0.5d
Axial tilt	?°
Albedo	0.03
Surface temp.	min mean max K K K
Atmospheric pressure	0 kPa

Elara (ee-lair'-a or ee'-lur-a, IPA or /'i:lərə/, Greek Ελάρη) is a moon of Jupiter. It was discovered by Charles Dillon Perrine at Lick Observatory in 1905 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 Jupiter VII. It was sometimes called "Hera".

It belongs to the Himalia group, five moons orbiting between 11 and 13 Gm from Jupiter at an inclination of about 27.5°.

External links

• Harvard College Observatory Bulletin, 178 (1905) 1
• Publications of the Astronomical Society of the Pacific, 17 (1905) 62
• Astronomische Nachrichten, 169 (1905) 43/44