Not an easy thing to do. The photographer was 2 miles away from the silhouettes, shooting on a 500mm lens with 2x Extender on a 1D Mark IV(Equivalent to a 1300mm lens). Everything has to click in place, from the moon's phase & trajectory, to sky clarity, this isn't something you can just go out and shoot:
Full Moon Silhouettes from Mark Gee on Vimeo.
Extremely well done Mark!