The originals used for this project were all procucts of NOAO. The credit for all of the original pictures goes to "National Optical Astronomy Observatory/ Association of Universities for Research in Astronomy/ National Science Foundation." According to the NOAO copyright page at http://www.noao.edu/image_gallery/copyright.html, their images may be used freely for "educational outreach activities composed by amateur astronomers". That's what this is.
Below I've listed the sources and credits for the pictures that were used for each of the Celestia objects.
Selden Ball, Jr. -- 23 August, 2003