(4857) Altgamia Main-belt Asteroid
Discovered on 29 March 1984 by C. S. Shoemaker at Palomar.
Where Altgamia is today
Seen from above the solar system on 2026-10-14: Altgamia is 2.31 au from the Sun and 1.86 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 4857 |
| Provisional designation | 1984 FM |
| Orbit class | Main-belt Asteroid |
| Diameter | 6.19 km (#8,646 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.349 |
| Rotation period | 9.03 hours |
| Absolute magnitude (H) | 13.28 |
| Orbital period | 3.61 years |
| Semi-major axis | 2.36 au |
| Perihelion – aphelion | 1.81 – 2.90 au |
| Eccentricity | 0.229 |
| Inclination | 24.5° |
| Closest distance between its orbit and Earth's (MOID) | 0.858 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.