Galatea (moon)

Galatea or Neptune VI, is the fourth closest moon to Neptune. It is named after Galatea, one of the Nereids of Greek legend.

Galatea

Discovery
Discovered by	Stephen P. Synnott
Discovered in	July 1989
Orbital characteristics
Epoch 18 August 1989
Semi-major axis	61 953 ± 1 km
Orbital eccentricity	0.00004 ± 0.00009
Orbital period	0.42874431 ± 0.00000001 d
Inclination	0.052 ± 0.011° (to Neptune equator) 0.06° (to local Laplace plane)
Is a moon of	Neptune
Physical characteristics
Dimensions	204×184×144 km (±~10 km)
Mass	2.12 ± 0.08 ×1018 kg
Mean density	0.75 ± 0.1 g/cm3
Rotation period	assumed synchronous
Axial tilt	~zero presumably
Albedo (geometric)	0.08
Surface temp.	~51 K mean (estimate)
Atmosphere	none

There is also an asteroid called 74 Galatea.

Galatea was found in late July 1989 from the images taken by the Voyager 2 probe. It was given the designation S/1989 N 4. The discovery was said (IAUC 4824) on August 2, 1989, but the text only talks of "10 frames taken over 5 days", giving a discovery date of sometime before July 28. The name was given on 16 September 1991.

It is not a sphere and shows no sign of any geological changes.

Other websites

Media related to Galatea (moon) at Wikimedia Commons

• Galatea Profile Archived 2007-08-01 at the Wayback Machine by NASA's Solar System Exploration