(9309) Platanus Main-belt Asteroid
Discovered on 20 September 1987 by E. W. Elst at Smolyan.
Named for Platanaceae, the plane family, with one genus and seven species. They grow wild mainly in the United States and Mexico, but they are also typical of southern France. Platanus acerifolia (London plane) reaches a height of almost 30 m and is widely planted in cities because of its resistance to air pollution. The brown, bristly fruits, hanging two to four together on a single stalk, persist over the winter.Naming citation (WGSBN Bull. 2, #9, 6), IAU / Minor Planet Center, via NASA/JPL
Where Platanus is today
Seen from above the solar system on 2026-10-14: Platanus is 3.01 au from the Sun and 2.64 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 9309 |
| Provisional designation | 1987 SS9 |
| Orbit class | Main-belt Asteroid |
| Diameter | 8.33 km (#6,282 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.111 |
| Absolute magnitude (H) | 13.8 |
| Orbital period | 5.70 years |
| Semi-major axis | 3.19 au |
| Perihelion – aphelion | 2.64 – 3.74 au |
| Eccentricity | 0.173 |
| Inclination | 2.62° |
| Closest distance between its orbit and Earth's (MOID) | 1.65 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.