(21728) Zhuzhirui Main-belt Asteroid
Discovered on 9 September 1999 by LINEAR at Socorro.
Zhu Zhirui (b. 1988) was awarded second place in the 2006 Intel International Science and Engineering Fair for his environmental sciences project. He attends the Shanghai Luwan High School, Shanghai, China.Naming citation (20060711/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Zhuzhirui is today
Seen from above the solar system on 2026-10-14: Zhuzhirui is 2.55 au from the Sun and 1.94 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 21728 |
| Provisional designation | 1999 RH136 |
| Orbit class | Main-belt Asteroid |
| Diameter | 3.29 km (#14,522 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.236 |
| Absolute magnitude (H) | 14.17 |
| Orbital period | 4.35 years |
| Semi-major axis | 2.66 au |
| Perihelion – aphelion | 2.51 – 2.82 au |
| Eccentricity | 0.0573 |
| Inclination | 15.3° |
| Closest distance between its orbit and Earth's (MOID) | 1.54 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also named after someone called Zhu
- (10388) Zhuguangya
- (20689) Zhuyuanchen
- (21731) Zhuruochen
- (224888) Cochingchu
- (256698) Zhuzhixin
- (391996) Zhunenghong
All asteroids named after someone called Zhu
Also discovered on 9 September 1999
- (12127) Mamiya
- (12130) Mousa
- (12589) Davidanand
- (12590) Ballantine
- (12591) Bergey
- (12592) Brianchen
- (12593) Shashlov
- (12594) Sidorclare
- (12595) Amandashaw
- (12596) Shukla
- (12597) Williamdaniel
- (12598) Sierra