Have you seen this picture? It aired Wednesday morning on the Early Today show on NBC. It shows a "Sonic Boom." In this case a fighter jet breaks the sound barrier during a training mission last month over the Gulf of Alaska.
The shape is called a "vapor cone." The visual phenomenon is seen sometimes, but not always, when the sound barrier is broken. Its been seen with nuclear blasts, after the space shuttle launches and when Apollo 11 launched on its way to a moon landing mission.
So what causes this phenomenon? Here's our best guess. A layer of water droplets gets trapped between two high-pressure surfaces of air. In humid conditions, condensation can gather in the trough between two crests of the sound waves produced by the jet. Like any jet contrail, over a period of time it dissipates. Pretty cool, huh?
