What Is a Sonic Boom? Here’s Everything You Need to Know About the Eardrum-Rattling Phenomenon
- The basic definition: A sonic boom is the thunder-like sound created when an object moves through the air faster than the speed of sound (about 767 mph at sea level). It happens when sound waves, which normally travel ahead of the object, get compressed into a single, powerful shockwave—like a wake from a boat, but in air.
- It’s not a single event on the ground: Many people think you hear one "boom" directly under the aircraft, but the noise actually trails the object in a cone-shaped pattern. This means anyone within that cone’s path on the ground will experience the boom as a sudden, loud double-crack—think of it as two quick gunshots in rapid succession.
- What causes the double boom effect: The first boom comes from the shockwave at the nose of the aircraft, and the second from the tail as the air rushes back in. For supersonic jets like fighter planes or the Concorde, the sound can rattle windows and shake buildings, though modern designs aim to soften it into a low "rumble."
- Why you rarely hear them from commercial flights: Since 1973, the FAA has banned supersonic flight over land in the U.S. due to the disruptive noise and potential property damage. That’s why the only sonic booms most people hear today come from military aircraft in test zones, rocket launches, or meteorites entering the atmosphere.
- The space connection: When NASA launches a rocket or the SpaceX Starship test flies, they often produce sonic booms during re-entry. These can be mistaken for earthquakes or explosions—and in Florida, locals near Cape Canaveral have learned to recognize the sharp, window-rattling sound as a sign of a successful mission.