(9650) Okadaira Main-belt Asteroid
Discovered on 17 December 1995 by T. Kobayashi at Oizumi.
The Okadaira Shell Mound located in Miho village, Ibaraki prefecture, was built on the south coast of Lake Kasumigaura about 7,000 to 3,500 years ago. The research by Sasaki and Iijima in 1879 is appreciated as “the Starting Point of Japanese Archaeology”. It was the first Japanese-only excavation.Naming citation (WGSBN Bull. 3, #13, 12), IAU / Minor Planet Center, via NASA/JPL
Where Okadaira is today
Seen from above the solar system on 2026-10-14: Okadaira is 2.47 au from the Sun and 1.77 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 9650 |
| Provisional designation | 1995 YG |
| Orbit class | Main-belt Asteroid |
| Diameter | 3.69 km (#13,480 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.247 |
| Rotation period | 57.0 hours |
| Absolute magnitude (H) | 14.49 |
| Orbital period | 3.46 years |
| Semi-major axis | 2.29 au |
| Perihelion – aphelion | 1.89 – 2.69 au |
| Eccentricity | 0.173 |
| Inclination | 2.53° |
| Closest distance between its orbit and Earth's (MOID) | 0.877 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.