NASA clarifies truth behind loud sonic booms from supersonic jets

The common understanding of sonic booms is that they occur only at the precise moment an aircraft surpasses the speed of sound. However, NASA has clarified this misconception, explaining that the phenomenon is continuous. A sonic boom accompanies an aircraft as long as it maintains supersonic speed, with its pressure waves traveling towards the surface.

When an aircraft flies faster than Mach 1, it outpaces the pressure waves it generates. This leads to rapid pressure changes known as shock waves. These waves emanate from various parts of the aircraft, including the nose, cockpit, wings, engine intakes, and tail. Each component can produce its own distinct wave.

The waves expand from the flight path, covering a wide area. This explains why multiple people in different locations can hear the same sonic boom. Altitude also plays a significant role; a boom generated at 55,000 feet can take nearly a minute to reach the ground, by which time the aircraft is miles ahead. The sound's characteristics can vary greatly, with some hearing a single sharp clap, others two distinct sounds, and some a softer noise, depending on the aircraft's shape, trajectory, and atmospheric conditions.

These acoustic challenges have historically limited commercial supersonic flights over land. NASA's research into sonic booms has led to the development of the experimental X-59 aircraft, designed to mitigate this noise.