We have used to following sources for information and pictures in our video and on this website:

http://www.bbc.co.uk/history/historic_figures/galilei_galileo.shtml

http://www-gap.dcs.st-and.ac.uk/~history/ Mathematicians/

http://www.kepler.arc.nasa.gov/johannes.html

http://www.mnsu.edu/emuseum/information/solarsystem/

http://www.nasa.gov

http://www.seds.org/billa/psc/theman.html

http://www.spacetoday.org/SolSys/Earth/AncientAstronomy.html

http://www.transitofvenus.org

http://transitofvenus.auckland.ac.nz/

http://www.uclan.ac.uk/facs/science/physastr/misc/horrock.htm

http://www.zebu.uoregon.edu/~js/glossary/ptolemy.html

Parker, Steve Galileo: and the universe London 1992

Gibbon, Edward: Decline and Fall of the Roman Empire, Reprinted 1979

Gingerich, Owen. The eye of heaven : Ptolemy, Copernicus, Kepler New York, 1993.

Miscrosoft Encarta Encyclopedia

NASA's 25th Anniversary (archived footage)