(128) Nemesis Main-belt Asteroid
Discovered on 25 November 1872 by J. C. Watson at Ann Arbor.
Where Nemesis is today
Seen from above the solar system on 2026-10-14: Nemesis is 2.60 au from the Sun and 2.49 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 128 |
| Provisional designation | A872 WA |
| Orbit class | Main-belt Asteroid |
| Diameter | 163 km (#64 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.0670 |
| Rotation period | 38.9 hours |
| Spectral type | C |
| Absolute magnitude (H) | 7.68 |
| Orbital period | 4.56 years |
| Semi-major axis | 2.75 au |
| Perihelion – aphelion | 2.40 – 3.10 au |
| Eccentricity | 0.127 |
| Inclination | 6.25° |
| Closest distance between its orbit and Earth's (MOID) | 1.41 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
More named asteroids discovered by J. C. Watson
- (79) Eurynome
- (93) Minerva
- (94) Aurora
- (100) Hekate
- (101) Helena
- (103) Hera
- (104) Klymene
- (105) Artemis
- (106) Dione
- (115) Thyra
- (119) Althaea
- (121) Hermione
← (127) Johanna · (129) Antigone →