20 Massalia
Lightcurve-based 3D-model of Massalia | |
| Discovery | |
|---|---|
| Discovered by | A. de Gasparis |
| Discovery site | Naples Obs. |
| Discovery date | 19 September 1852, 04:31 |
| Designations | |
| (20) Massalia | |
| Pronunciation | /mæˈseɪliə/ |
Named after | Marseille (French city) |
| Massilia /mæˈsɪliə/ | |
| main belt · Massalia | |
| Adjectives | Massalian /mæˈseɪliən/ |
| Orbital characteristics | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 164.08 yr (59,929 d) |
| Aphelion | 2.7514 AU |
| Perihelion | 2.0662 AU |
| 2.4088 AU | |
| Eccentricity | 0.1422 |
| 3.74 yr (1,366 d) | |
| 12.443° | |
| 0° 15m 48.96s / day | |
| Inclination | 0.7087° |
| 206.11° | |
| 2021-Nov-04 | |
| 256.58° | |
| Physical characteristics | |
| Dimensions | 160×145×132 km 160×145×130 km |
| 145.50±9.3 km | |
| Mass | 5.2×1018 kg 5.67×1018 kg |
Mean density | 3.54±0.85 g/cm3 |
| 8.098 h | |
| 0.210 | |
| Tholen = S SMASS = S | |
| 8.3 to 12.0 | |
| 6.50 | |
| 0.186" to 0.058" | |
20 Massalia is a stony asteroid and the parent body of the Massalia family located in the inner region of the asteroid belt, approximately 145 kilometers (90 miles) in diameter. Discovered by Italian astronomer Annibale de Gasparis on 19 September 1852, it was named for the Latin name of the French city of Marseille, from which the independent discover Jean Chacornac sighted it the following night. It was the first asteroid that was not assigned an iconic symbol by its discoverer.
It came to opposition 179 degrees from the Sun on 16 June 2023, and came to aphelion (farthest distance from the Sun) on 17 September 2023.