What changes have been made to Celestia since the last version?
The developers maintain a list of all new functionality and bug fixes in the Celestia ChangeLog, which is located at SourceForge: http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/celestia/celestia/ChangeLog. Look at the top-most entry in the list, to the right of where it says “Revision #.##”, click the “(view)” link to display the most recent ChangeLog.