4 of 10:
The transit of Venus makes it's way across the sun as photographed by the Sydney Observatory, Tuesday, June 8, 2004. Stargazers in Sydney and around the world gathered at observatories and huddled by telescopes Tuesday to watch a small dark disc creep across the face of the sun in one of the rarest of celestial spectacles, a transit of Venus.The sight had special significance for Australians, this country's east coast was "discovered" by British explorer James Cook on his way home from viewing the 1769 transit in Tahiti. The image was taken in the light of hydrogen alpha which was impossible to do at previous transits.
(AP Photo/Sydney Observatory, HO)