(9003) Ralphmilliken Main-belt Asteroid
Discovered on 24 October 1981 by S. J. Bus at Palomar.
Ralph E. Milliken (b. 1978) is a planetary science professor at Brown University. He has developed techniques for deriving the water content of hydrated minerals in meteorites and asteroids using reflectance spectroscopy and has applied them toward interpreting the surface composition of Ceres.Naming citation (MPC batch dated 2014-07-12), IAU / Minor Planet Center, via NASA/JPL
Where Ralphmilliken is today
Seen from above the solar system on 2026-10-14: Ralphmilliken is 2.86 au from the Sun and 3.18 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 9003 |
| Provisional designation | 1981 UW21 |
| Orbit class | Main-belt Asteroid |
| Diameter | 15.1 km (#3,112 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.0520 |
| Rotation period | 13.3 hours |
| Absolute magnitude (H) | 13.2 |
| Orbital period | 4.64 years |
| Semi-major axis | 2.78 au |
| Perihelion – aphelion | 2.57 – 2.99 au |
| Eccentricity | 0.0762 |
| Inclination | 5.34° |
| Closest distance between its orbit and Earth's (MOID) | 1.58 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also named after someone called Ralph
- (9850) Ralphcopeland
- (9881) Sampson
- (9902) Kirkpatrick
- (10491) Chou
- (11377) Nye
- (12956) Ralphwijers
- (13852) Ford
- (33594) Ralphlawton
- (50427) Ralphmerrifield
- (172191) Ralphmcnutt
All asteroids named after someone called Ralph
Also discovered on 24 October 1981
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- (4623) Obraztsova
- (6366) Rainerwieler
- (7049) Meibom
- (7160) Tokunaga
- (7326) Tedbunch
- (8807) Schenk
- (8808) Luhmann
- (9536) Statler
- (10033) Bodewits
- (10707) Prunariu
- (11267) Donaldkessler