Pan (moon)
Color photo of Pan by Cassini in March 2017 | |
| Discovery | |
|---|---|
| Discovered by | M. R. Showalter |
| Discovery date | July 16, 1990 |
| Designations | |
Designation | Saturn XVIII |
| Pronunciation | /ˈpæn/ |
Named after | Πάν Pān |
| S/1981 S 13 | |
| Adjectives | Pandean /pænˈdiːən/ |
| Orbital characteristics | |
| 133584.0±0.1 km | |
| Eccentricity | 0.0000144±0.0000054 |
| 0.575050718 d (13.801217 h) | |
| Inclination | 0.0001°±0.0004° |
| Satellite of | Saturn |
| Group | Shepherd moon of the Encke Gap |
| Physical characteristics | |
| Dimensions | 34.6 × 28.2 × 21.0 km (± 0.4 × 0.4 × 1.0 km): 2 |
| 27.4±0.6 km: 2 | |
| Volume | 10748 km3: 8 |
| Mass | (4.30±0.22)×1015 kg: 3 |
Mean density | 0.400±0.031 g/cm3: 3 |
| 0.0111–0.0169 m/s2: 3 | |
| 0.006 km/s at longest axis to 0.007 km/s at poles | |
| synchronous | |
| zero | |
| Albedo | 0.5 |
| Temperature | ≈ 78 K |
Pan is the innermost named moon of Saturn. It is approximately 35 kilometres across and 23 km wide and orbits within the Encke Gap in Saturn's A Ring. Pan is a ring shepherd and is responsible for keeping the Encke Gap free of ring particles. It is sometimes described as having the appearance of a walnut, or ravioli.
Pan was discovered by Mark R. Showalter in 1990 from analysis of old Voyager 2 probe photos and received the provisional designation S/1981 S 13 because the discovery images dated back to 1981.