What sounds does a falling meteorite make?
Big fireballs can produce delayed sonic booms and rumbles like thunder, and falling stones may whistle or buzz in their final moments. A few people also report hissing heard at the same moment as the flash.
Fireballs that come low enough to drop meteorites can be surprisingly noisy, and witnesses describe a range of sounds.
The most common are sonic booms. A meteoroid travels many times faster than sound, creating a shock wave that spreads outwards like the wake of a boat. Because the fireball is often 20 to 50 km away, and sound travels only about a third of a kilometre per second, the booms usually arrive between one and a few minutes after the light has vanished. Witnesses often describe a series of bangs like gunfire, followed by long rolling rumbles, as the sound arrives from different parts of a long path. Fragmentation adds extra booms. Hearing them is an exciting sign: it suggests the object penetrated deep into the atmosphere, which raises the chance that meteorites reached the ground.
Some people near the fall zone hear the stones themselves. Falling through the lower air in dark flight, fragments can make a whistling, whirring or buzzing sound, sometimes compared with a passing aircraft or a swarm of bees, followed by a thud as they hit the ground.
The strangest are electrophonic sounds: hissing, crackling or sizzling heard at the very same moment as the flash. Sound waves could not travel that fast, so for a long time such reports were dismissed. The leading explanation is that a bright fireball gives off very low-frequency radio waves or flickering light, which travel at the speed of light and make nearby objects such as wire fences, dry leaves, hair or glasses vibrate slightly, producing sound close to the listener. If you witness a fireball, note any sounds and when you heard them; they are valuable clues for scientists.