Most of the images were obtained from NASA's Jet Propulsion Laboratory (policy) and the Space Telescope Science Institute (policy).

Campell, Ann-Jeanette. Amazing Space: A Book of Answers for Kids. New York: The New York Public Library, 1997.

Editors of Time-Life Books. Voyage Through The Universe: The Far Planets. Virginia: Time-Life Books Inc., 1990.

Levy, David H. Skywatching. Australia: US Weldon Owen Inc., 1994.

Morrison, Philip and Phylis. The Ring of Truth. Philip and Phylis Morrison, 1987.

Watters, Thomas R. Planets: A Smithsonian Guide. Boston, MA: Ligature Inc., 1995.