(991) McDonalda Main-belt Asteroid
Discovered on 24 October 1922 by O. Struve at Williams Bay.
Where McDonalda is today
Seen from above the solar system on 2026-10-14: McDonalda is 3.01 au from the Sun and 3.90 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 991 |
| Provisional designation | A922 UC |
| Orbit class | Main-belt Asteroid |
| Diameter | 38.6 km (#1,011 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.0400 |
| Spectral type | C: |
| Absolute magnitude (H) | 11.23 |
| Orbital period | 5.55 years |
| Semi-major axis | 3.14 au |
| Perihelion – aphelion | 2.63 – 3.65 au |
| Eccentricity | 0.163 |
| Inclination | 2.07° |
| Closest distance between its orbit and Earth's (MOID) | 1.61 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
More named asteroids discovered by O. Struve
← (990) Yerkes · (992) Swasey →