(8931) Hirokimatsuo Main-belt Asteroid
Discovered on 6 January 1997 by T. Kobayashi at Oizumi.
Hiroki Matsuo, former director general at the Institute of Space and Astronautical Science, has engaged in space development since the launch of the first Japanese satellite. He contributed to the promotion of interplanetary missions while establishing an engineering basis for the Comet 1P/Halley exploration mission.Naming citation (20031110/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Hirokimatsuo is today
Seen from above the solar system on 2026-10-14: Hirokimatsuo is 2.69 au from the Sun and 3.61 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 8931 |
| Provisional designation | 1997 AC4 |
| Orbit class | Main-belt Asteroid |
| Rotation period | 3.19 hours |
| Absolute magnitude (H) | 13.77 |
| Orbital period | 3.63 years |
| Semi-major axis | 2.36 au |
| Perihelion – aphelion | 1.82 – 2.90 au |
| Eccentricity | 0.228 |
| Inclination | 2.22° |
| Closest distance between its orbit and Earth's (MOID) | 0.810 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also named after someone called Hiroki
All asteroids named after someone called Hiroki
Also discovered on 6 January 1997
- (7618) Gotoyukichi
- (8930) Kubota
- (8932) Nagatomo
- (8933) Kurobe
- (9107) Narukospa
- (17681) Tweedledum
- (18553) Kinkakuji
- (23638) Nagano
More named asteroids discovered by T. Kobayashi
- (4807) Noboru
- (5924) Teruo
- (6275) Kiryu
- (6276) Kurohone
- (6346) Syukumeguri
- (6414) Mizunuma
- (6418) Hanamigahara
- (6420) Riheijyaya
- (6422) Akagi
- (6423) Harunasan
- (6462) Myougi
- (6531) Subashiri
← (8930) Kubota · (8932) Nagatomo →