(52228) Protos Outer Main-belt Asteroid
Discovered on 5 September 1977 by L. D. Schmadel at La Silla.
This Greek word indicates the discoverer's first minor planet detection.Naming citation (20040107/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Protos is today
Seen from above the solar system on 2026-10-14: Protos is 3.59 au from the Sun and 4.53 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 52228 |
| Provisional designation | 1977 RN |
| Orbit class | Outer Main-belt Asteroid |
| Diameter | 5.59 km (#9,587 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.271 |
| Absolute magnitude (H) | 13.59 |
| Orbital period | 5.74 years |
| Semi-major axis | 3.21 au |
| Perihelion – aphelion | 2.80 – 3.61 au |
| Eccentricity | 0.126 |
| Inclination | 27.9° |
| Closest distance between its orbit and Earth's (MOID) | 1.83 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.