This movie taken on June, 8 2004 is one of those rare celestial events, one not seen by any person now alive. The "Venus transit" -- the apparent crossing of our planetary neighbor in front of the Sun -- was captured from the unique perspective of NASA's Sun-observing TRACE spacecraft. The movie is in the extreme ultrviolet.
The last "Venus transit" occurred more than a century ago, in 1882, and was used to compute the distance from the Earth to the Sun. Scientists with NASA's Kepler mission hope to discover Earth-like planets outside our solar system by searching for transits of other stars by planets that might be orbiting them.
If people miss the June 8 Venus transit, they will have another chance in 2012 (June 6). After that, there will not be another Venus transit until 2117 (December 11).