Every now and then a photographer manages to capture a truly spectacular sight, and the image becomes instantly famous—so far, I've seen this one on the news, in newspapers, and in numerous places on the internet. Astronomical photographer Thierry Legault (he's authored several books on the subject, the most recent of which, The Art of Astrophotography, will be published in English translation in late 2009) took this "transit" photograph from a location in Florida, using a Canon 5D Mark II mounted to a Takahashi TOA-130 refractor telescope (effective focal length 2,200mm). Shooting through a Baader solar filter, the camera was set on ISO 100 with a 1/8000th shutter speed. Remarkably, the Shuttle Atlantis is traveling at 15,500 miles per hour, and the transit itself lasted only eight-tenths of a second, which gives you an idea of the depth of knowledge and preparedness required of the photographer. This transit was viewable from a swath of territory on Earth only three and a half miles wide.
The picture above, however, is a radical crop. Some great photographs are not designs that are composed merely for pictorial effect, but in this case you really must take a look at the full photograph at Thierry's website (fourth one down)—it's as stark and emblematic as any work of modern art, aesthetically perfect in addition to being a photographic report of something real and seldom seen.
(Thanks to Ibrahima Béla Sow)