It is maintained by Jet Propulsion Laboratory (JPL) and NASA and provides data for all known asteroids and several comets, including orbital parameters and diagrams, physical diagrams, close approach details, radar astrometry, discovery circumstances, alternate designations and lists of publications related to the small body.
[3] As of August 2013,[update] (planetary ephemeris DE431) close-approach data is available for the major planets and the 16 most massive asteroids.
The JPL Small-Body Database close approach table lists a linearized uncertainty.
The visualized orbits use unreliable 2-body methods, and hence should not be used for accurately determining the time of perihelion passage or planetary encounter circumstances.
For accurate ephemerides use the JPL Horizons On-Line Ephemeris System that handles the n-body problem using numerical integration.