(21117) Tashimaseizo Main-belt Asteroid
Discovered on 30 September 1992 by Endate, K., Watanabe, K. at Kitami.
Seizo Tashima (b. 1940) is well-known as an author of illustrated books. He has won many national and international prizes for his books and pictures.Naming citation (MPC batch dated 2017-03-12), IAU / Minor Planet Center, via NASA/JPL
Where Tashimaseizo is today
Seen from above the solar system on 2026-10-14: Tashimaseizo is 2.49 au from the Sun and 1.98 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 21117 |
| Provisional designation | 1992 SB13 |
| Orbit class | Main-belt Asteroid |
| Diameter | 3.87 km (#13,064 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.356 |
| Rotation period | 3.80 hours |
| Absolute magnitude (H) | 14.13 |
| Orbital period | 3.45 years |
| Semi-major axis | 2.29 au |
| Perihelion – aphelion | 2.07 – 2.50 au |
| Eccentricity | 0.0940 |
| Inclination | 3.57° |
| Closest distance between its orbit and Earth's (MOID) | 1.09 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.