The image shows NASA's space shuttle Atlantis just minutes from reaching the Hubble space telescope, as both are in transit in front of the sun. Captured shortly after noon on Wednesday, the photograph clearly took immense planning on Mr Legault's part.
Having used the Celestial Observer website to determine the ideal time and location from which to capture the image, he left his home in Paris en route to Florida. With him came the equipment on which the image would be captured - including a Canon EOS 5D Mark II digital SLR, Takahashi TOA-130 refractor telescope, and Baader solar prism. On his arrival, the Floridian thunderstorms common at this time of year threatened to nix the photo opportunity, and Mr Legault told the Daily Mail that his greatest challenge was to find a hole in the clouds.
Some 370 miles above his head, Atlantis was within several minutes of reaching the space telescope. The shuttle's crew are tasked with servicing Hubble for the fifth and final time, repairing two failed instruments, adding two new ones, and performing a general overhaul that should see the telescope through to its 24th year in service. At the time of this writing, that mission continues.
With the shuttle measuring just 35 meters in length, and Hubble itself around 13 meters, the difficulty of the shot is obvious. Together, the pair were moving at a whopping seven kilometers per second, and would transit the sun in just 0.8 seconds. Triggering his shutter at four frames per second some two seconds before the expected transit, Mr Legault captured a total of 16 frames at 1/8000 second, with the EOS 5D Mark II set to ISO 100 equivalent.
The results speak for themselves. The outline of Atlantis is clearly visible in silhouette, alongside the speck that is Hubble. In the background, the sun is an eerie yellow ball, with 95% of its light reflected away by the prism.
Looking over Mr Legault's website, it is clear he's no stranger to capturing exceptional astronomical images. This week's capture mirrors an earlier photo shot from Normandie, France in 2006 - that image showing a solar transit with Atlantis having just departed the International Space Station. Aspiring astrophotographers will find plenty of interesting material on the site beyond the photos, as well - Mr Legault has thoughtfully provided a number of articles sharing his experience in selecting and using the necessary equipment.
Hearty congratulations to Mr Legault on a truly unique capture!
UPDATED 2009-05-16 13:15ET: The page containing the high-res version of the image on Mr Legault's site seems to have been removed for some reason - perhaps due to bandwidth issues, given the coverage the story has received worldwide. For now we've removed the links from this article, but on the offchance that it will later reappear, this page hosted the high-res image. In the meantime, we recommend viewing a slightly smaller version of the image on the Daily Mail's website.
We've also caught an error in the link to the main page of Mr Legault's website in this article, which has now been corrected.