Thalassa (moon)
Thalassa (1989 N5) seen by Voyager 2 on 23 August 1989 | |
| Discovery | |
|---|---|
| Discovered by | Richard J. Terrile and Voyager Imaging Team |
| Discovery date | September 1989 |
| Designations | |
Designation | Neptune IV |
| Pronunciation | /θəˈlæsə/ |
Named after | Θάλασσα Thalassa |
| Adjectives | Thalassian /θəˈlæsiən/ |
| Orbital characteristics | |
| Epoch 18 August 1989 | |
| 50074.44 km | |
| Eccentricity | 0.00176±0.00054 |
| 0.31148444±0.00000006 d | |
| Inclination |
|
| Satellite of | Neptune |
| Physical characteristics | |
| Dimensions | (108±6) × (100±12) × (52±6) km |
| 41±3 km | |
| Mass | ~3.54×1017 kg (calculated) |
Mean density | 1.23±0.43 g/cm3 |
| synchronous | |
| zero | |
| Albedo | 0.091 |
| Temperature | ~51 K mean (estimate) |
| 23.32 | |
Thalassa /θəˈlæsə/, also known as Neptune IV, is the second-innermost satellite of Neptune. Thalassa was named after sea goddess Thalassa, a daughter of Aether and Hemera from Greek mythology. "Thalassa" is also the Greek word for "sea".