Sources for Earth:

"Earth [Planet]." World Book Multimedia Encyclopedia. Chicago: World Book 
Inc., 1997.

"Earth Fact Sheet," National Space Science Data Center. Online. 14 July 2000.
http://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html 

"Moon Fact Sheet," National Space Science Data Center. Online. 14 July 2000. 
http://nssdc.gsfc.nasa.gov/planetary/factsheet/moonfact.html 

McManus, Jason, Ed. The Near Planets. Richmond, Virginia, 
Time-Life Books Inc, 1989.

McNab, David, and James Younger. The Planets. New Haven and London: Yale 
University Press, 1999.

Kaufmann III, William J. and Roger A. Freedman. Universe, Fifth Edition. 
W.H. Freeman and Company: New York. 1999. 

Vilas, Faith. The New Solar System. Ed. J. Kelly Beatty, Carolyn Collins 
Peterson, Andrew Chaikin. Cambridge, Massachussets: Cambridge University 
Press, 1999.

Photo Credits for Earth:

Earth: Earth with Hurricane Andrew taken by the NOAA GOES-7 satellite on 
August 25, 1992. NASA ID #: PIA01462 or P45835. Courtesy of NOAA/JPL/NASA.

Earth animation: from Macmillan's "50,000 Ultimate Web Graphics". Courtesy 
of Macmillan Publishing. http://www.macmillansoftware.com

Earth: Taken by the GOES-8 satellite. Courtesy of NOAA/NASA. 

Earth magnetic field: Drawn by Margaret Hsu.

Earth: View of Africa and Saudi Arabia from Apollo 17.  Courtesy of NSSDC 
and NASA. NASA photo number(s): 72-HC-928, 72-H-1578, or AS17-148-22727.   
http://nssdc.gsfc.nasa.gov/image/planetary/earth/apollo17_earth.jpg

Earth rise: view of earth from the moon taken on the Apollo 08 mission. 
Courtesy of NASA/NSSDC.

Astronaut next to boulder: Astronaut Harrison Schmitt standing next to a 
boulder at the Taurus-Lithow site during 3rd EVA. NASA PR: AS17-140-21498. 
Courtesy of NASA/NSSDC.

Full moon picture: (clem_full_moon_strtrl.jpg) Star Tracker mosaic. 
Images taken by the Clementine Space craft on March 15, 1994. North is up 
and the bright crater is Tycho. Courtesy of NASA/NSSDC.

Pangaea: Map of Pangaea. from ZINE375. 
http://www.eserver.org/journals/zine375/zine9.html  

Ozone Diagram: levels of ozone at the south pole from 1979 to 1992. 
Courtesy of NASA Goddard Space Flight Center.