Eclipse shadows are cast by undrawn objects.
If one creates an ssc file defining a set of (spherical) objects at the same location
and uses Beginning and Ending declarations to control when they are supposed to be drawn,
Eclipse shadows are cast by the undrawn objects
causing half of the drawn object to be in the dark.
If one types a Ctrl-E several times, turning eclipse shadows off and on, one can see the dark side become visible and then become shaded again.
If one inserts an invalid declaration, so that only the first object in the ssc file is drawn, no eclipse shadows are seen.
This can be seen by installing this Addon:
http://www.lns.cornell.edu/~seb/celestia/begend.zip
(Which I've updated to comply with current Addon directory standards. It also includes a Cel:// url to take you to this viewpoint.)
System config:
256MB 500MHz P3, WinXP Pro SP1
128MB GF4 Ti4200, drivers v 56.72
Celestia built from CVS 21-Jul-04
