Asteroids Orbits
http://www.minorplanetcenter.net/iau/MPC_Documentation.html

Comets Orbits
http://www.minorplanetcenter.net/iau/info/CometOrbitFormat.html
http://ssd.jpl.nasa.gov/dat/ELEMENTS.COMET

Observations
http://www.minorplanetcenter.net/iau/info/OpticalObs.html

