(21860) Joannaguy Main-belt Asteroid
Discovered on 10 October 1999 by LINEAR at Socorro.
Joanna Christine Guy (b. 1991) is a finalist in the 2005 Discovery Channel Young Scientist Challenge (DCYSC), a middle school science competition, for her behavioral science project. She attends the Southern Middle School, Oakland, Maryland.Naming citation (20051019/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Joannaguy is today
Seen from above the solar system on 2026-10-14: Joannaguy is 2.60 au from the Sun and 2.55 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 21860 |
| Provisional designation | 1999 TX180 |
| Orbit class | Main-belt Asteroid |
| Diameter | 4.80 km (#11,022 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.232 |
| Absolute magnitude (H) | 14.08 |
| Orbital period | 4.40 years |
| Semi-major axis | 2.68 au |
| Perihelion – aphelion | 2.60 – 2.77 au |
| Eccentricity | 0.0329 |
| Inclination | 3.32° |
| Closest distance between its orbit and Earth's (MOID) | 1.61 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also named after someone called Joanna
All asteroids named after someone called Joanna
Also discovered on 10 October 1999
- (12932) Conedera
- (13408) Deadoklestic
- (16092) Anudeepgolla
- (17180) Rupertli
- (20623) Davidyoung
- (20648) Ryukihyodo
- (20649) Miklenov
- (20650) Saillenfest
- (22898) Falce
- (22936) Ricmccutchen
- (22937) Nataliavella
- (22938) Brilawrence