Oh boy, I was waiting for this. Whenever NASA has a launch, there's always some cool photography to follow.
What you're looking at is called a "shock egg," or the Prandtl-Glauert singularity, or a shockwave that compresses air and forces the vapor out of it. You see this kind of stuff a lot in photographs trailing behind fighter jets, but it's especially awesome when it happens to rockets. According to NASA, the shot was taken by one Scott Andrews, who used a Canon of some sort.
This shot is too pretty for the small version up above. Click Continue and I'll give it the big screen treatment, as well as provide some words from NASA.
Click on the image to make it larger:
CAPE CANAVERAL, Fla. - A bow shock forms around the Constellation Program's 327-foot-tall Ares I-X test rocket traveling at supersonic speed. The rocket produces 2.96 million pounds of thrust at liftoff and goes supersonic in 39 seconds. Liftoff of the 6-minute flight test from Launch Pad 39B at NASA's Kennedy Space Center in Florida was at 11:30 a.m. EDT Oct. 28. This was the first launch from Kennedy's pads of a vehicle other than the space shuttle since the Apollo Program's Saturn rockets were retired. The parts used to make the Ares I-X booster flew on 30 different shuttle missions ranging from STS-29 in 1989 to STS-106 in 2000. The data returned from more than 700 sensors throughout the rocket will be used to refine the design of future launch vehicles and bring NASA one step closer to reaching its exploration goals. For information on the Ares I-X vehicle and flight test, visit http://www.nasa.gov/aresIX. Photo courtesy of Scott Andrews, Canon