Ka-Boom!

Here's a cool article from National Geographic:


Photo in the News: Jet's "Sonic Boom Cloud" Caught
Photo: Jet breaking sound barrier

Photograph courtesy U.S. Navy



August 8, 2005—A U.S. Navy photographer with lightning-fast reflexes captured this image of a fighter plane blasting through a "sonic boom cloud" as the jet broke the sound barrier. Petty Officer 3rd Class Jonathan Chandler shot the picture as the F/A-18F Super Hornet blew past the aircraft carrier U.S.S. Kitty Hawk in the Philippine Sea on July 27.

Despite its name, the sonic boom cloud doesn't always come with a sonic boom, and it's not a shock wave of the sound barrier being broken. The clouds only occur in unique weather conditions, when aircraft fly fast enough to cool the air around them, causing moisture in the air to condense into clouds. These halos of vapor appear for only a few seconds when aircraft reach speeds just below or just above the speed of sound (741 miles an hour/1,193 kilometers an hour).

But you don't have to be a top-gun photographer to see a sonic boom cloud. Several observers reported seeing one two days before this picture was taken, as the space shuttle Discovery reached supersonic speed soon after its July 25 launch.

—Blake de Pastino