(21581) Ernestoruiz Main-belt Asteroid
Discovered on 17 September 1998 by LONEOS at Anderson Mesa.
Ernesto Ruiz (b. 1958) has played a key role in numerous radar experiments on minor planets as an electronics technician and telescope operator at the Arecibo Observatory.Naming citation (20080718/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Ernestoruiz is today
Seen from above the solar system on 2026-10-14: Ernestoruiz is 2.89 au from the Sun and 3.47 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 21581 |
| Provisional designation | 1998 SD58 |
| Orbit class | Main-belt Asteroid |
| Diameter | 12.9 km (#3,768 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.118 |
| Absolute magnitude (H) | 12.56 |
| Orbital period | 5.25 years |
| Semi-major axis | 3.02 au |
| Perihelion – aphelion | 2.86 – 3.18 au |
| Eccentricity | 0.0521 |
| Inclination | 9.69° |
| Closest distance between its orbit and Earth's (MOID) | 1.90 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also named after someone called Ernesto
- (15004) Vallerani
- (18498) Cesaro
- (21236) Moneta
- (34587) Vieiraneto
- (39699) Ernestocorte
- (95951) Ernestopalomba
- (120361) Guido
All asteroids named after someone called Ernesto
Also discovered on 17 September 1998
- (10938) Lorenzalevy
- (11377) Nye
- (11378) Dauria
- (12909) Jaclifford
- (12910) Deliso
- (12911) Goodhue
- (12912) Streator
- (13326) Ferri
- (13327) Reitsema
- (13328) Guetter
- (13332) Benkhoff
- (13333) Carsenty