
Asteroid, Comet, and Satellite Catalogs
=======================================

After learning to program with PyEphem,
you will probably want to download the orbital elements
of comets or asteroids that interest you,
or perhaps coordinates for stars and other fixed objects.
Here are a few sources from which such data may be obtained:

https://celestrak.org/NORAD/elements/

 Orbital elements for man-made earth satellites are available from NORAD,
 whose Two-Line Element format can be understood
 by PyEphem's ``readtle()`` function.

http://toyvax.glendale.ca.us/

 This page has elements in ephem format
 for several of our longer-lived space probes.

https://xephem.github.io/XEphem/Site/help/xephem.html#mozTocId468501

 If you need more information about the XEphem database format itself,
 here is the link where the format is defined
 in XEphem's own documentation.
