JPL Solar System Dynamics WWW Site

The new JPL solar system dynamics WWW site is being made available to the public at ``http://ssd.jpl.nasa.gov/''. The site includes, but is not limited to, the following features: * simple ephemeris generation for planets, satellites, asteroids and comets * physical and orbital parameters for the planets and their satellites * asteroid and comet observer tools for object identification and listing all objects observable from a given location * Earth close-approaches by asteroids and comets (past and future) * custom table generation of up-to-date asteroid and comet orbital elements * radar astrometry data of asteroids and comets * distribution graphs of the asteroids and comets within the inner solar system * ecliptic-plane orbit plots of the inner and outer solar system * searchable asteroid discovery circumstances * description of great comets in history * spacecraft in heliocentric orbits (list of names, launch dates, mission, and country of origin) Data contained within this site will be updated regularly and new features will be added in the future (such as discovery circumstances for comets). The JPL solar system dynamics WWW site is designed to complement ``JPL's On-Line Solar System Data Service'' (J.D. Giorgini et al., BAAS 28:1158) known as the Horizons system which is available via telnet to host ssd.jpl.nasa.gov on port 6775.