(31674) Westermann Main-belt Asteroid
Discovered on 7 May 1999 by CSS at Catalina.
Mathilde Westermann (b. 1991) is an American science operations and GIS engineer at the University of Arizona, who planned science observations for the OSIRIS-REx mission and develops software to enable spatial registration of microscopic data produced from returned extraterrestrial samples. She is a desert-loving Tucson native with husband, son, and dog.Naming citation (WGSBN Bull. 3, #6, 10), IAU / Minor Planet Center, via NASA/JPL
Where Westermann is today
Seen from above the solar system on 2026-10-14: Westermann is 3.00 au from the Sun and 3.50 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 31674 |
| Provisional designation | 1999 JD9 |
| Orbit class | Main-belt Asteroid |
| Diameter | 5.48 km (#9,736 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.234 |
| Rotation period | 6.94 hours |
| Absolute magnitude (H) | 13.44 |
| Orbital period | 4.81 years |
| Semi-major axis | 2.85 au |
| Perihelion – aphelion | 2.65 – 3.05 au |
| Eccentricity | 0.0696 |
| Inclination | 14.3° |
| Closest distance between its orbit and Earth's (MOID) | 1.69 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.