(21656) Knuth Main-belt Asteroid
Discovered on 9 August 1999 by Pravec, P., Kusnirak, P. at Ondrejov.
Donald E. Knuth (b. 1938), professor of computer science at Stanford University, is author of The Art of Computer Programming, the fine typesetting system TeX and the METAFONT system. TeX has been used to produce a lot of the world's scientific literature in physics and mathematics, including the Minor Planet Circulars.Naming citation (20010509/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Knuth is today
Seen from above the solar system on 2026-10-14: Knuth is 2.26 au from the Sun and 1.30 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 21656 |
| Provisional designation | 1999 PX1 |
| Orbit class | Main-belt Asteroid |
| Diameter | 6.28 km (#8,534 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.0590 |
| Absolute magnitude (H) | 14.6 |
| Orbital period | 4.46 years |
| Semi-major axis | 2.71 au |
| Perihelion – aphelion | 2.09 – 3.32 au |
| Eccentricity | 0.227 |
| Inclination | 9.26° |
| Closest distance between its orbit and Earth's (MOID) | 1.09 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also named after someone called Donald
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- (4794) Bogard
- (6107) Osterbrock
- (6478) Gault
- (6688) Donmccarthy
- (8875) Fernie
- (9122) Hunten
- (9177) Donsaari
- (9295) Donaldyoung
- (9448) Donaldavies
- (11267) Donaldkessler
- (11419) Donjohnson
All asteroids named after someone called Donald