Don’t peek at the answer until you’ve given this a good try! Then, scroll down a bit and the truth will be revealed to you.

Credit: U.S. Navy photo by Ensign John Gay.

What in the world is it?

Talk about extreme speeds, this photo shows an F/A-18 Hornet assigned to Strike Fighter Squadron One Five One breaking the sound barrier in the skies over the Pacific Ocean. What that means is that you can use your eyes to see what you normally hear — a Sonic Boom!

Sonic Booms occur when a jet travels faster than the speed of sound (761 miles per hour). In this case the F/A-18 Hornet was traveling at 750 miles per hour. At this speed, the waves of sound emitted by the plane cannot precede the plane, so they accumulate in a cone behind it. If moisture in the air condenses within this cone, the “sound” becomes visible. The origin of this cloud is still debated.