(21000) L'Encyclopedie Main-belt Asteroid
Discovered on 26 January 1987 by E. W. Elst at La Silla.
The Encyclopédie or Dictionnaire raisonné des sciences, des arts et des métiers (1751-1772), by Diderot and d´Alembert, may be considered the principal work of the Age of Enlightenment.Naming citation (20030106/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where L'Encyclopedie is today
Seen from above the solar system on 2026-10-14: L'Encyclopedie is 2.72 au from the Sun and 1.98 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 21000 |
| Provisional designation | 1987 BY1 |
| Orbit class | Main-belt Asteroid |
| Diameter | 5.89 km (#9,104 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.0670 |
| Absolute magnitude (H) | 15.02 |
| Orbital period | 4.10 years |
| Semi-major axis | 2.56 au |
| Perihelion – aphelion | 1.97 – 3.15 au |
| Eccentricity | 0.229 |
| Inclination | 12.9° |
| Closest distance between its orbit and Earth's (MOID) | 1.00 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.