(21999) Disora Main-belt Asteroid
Discovered on 7 December 1999 by F. Mallia at Campo Catino.
Mario Di Sora is founder and manager of the Campo Catino Observatory. A lawyer by profession, as president of the Italian section of the International Dark Sky Association, he has promoted several regional laws on light pollution in Italy, notably by making Rome the first dark-sky capital in the world.Naming citation (20010509/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Disora is today
Seen from above the solar system on 2026-10-14: Disora is 2.95 au from the Sun and 3.41 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 21999 |
| Provisional designation | 1999 XS38 |
| Orbit class | Main-belt Asteroid |
| Diameter | 5.49 km (#9,731 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.158 |
| Absolute magnitude (H) | 13.29 |
| Orbital period | 4.35 years |
| Semi-major axis | 2.66 au |
| Perihelion – aphelion | 2.24 – 3.09 au |
| Eccentricity | 0.158 |
| Inclination | 14.3° |
| Closest distance between its orbit and Earth's (MOID) | 1.23 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also named after someone called Mario
- (5329) Decaro
- (5346) Benedetti
- (8106) Carpino
- (9680) Molina
- (10423) Dajcic
- (11165) Mariocabrera
- (11454) Mariomelita
- (12811) Rigonistern
- (15825) Capecchi
- (15837) Mariovalori
- (17466) Vargasllosa
- (20195) Mariovinci
All asteroids named after someone called Mario
Also discovered on 7 December 1999
- (13438) Marthanalexander
- (13845) Jillburnett
- (13848) Cioffi
- (13849) Dunn
- (13850) Erman
- (13852) Ford
- (13853) Jenniferfritz
- (14225) Alisahamilton
- (14226) Hamura
- (14230) Mariahines
- (14679) Susanreed
- (16118) Therberens