A “shooting star” is the common term for a meteor, the visible streak of light produced when a small piece of space rock, called a meteoroid, enters the Earth’s atmosphere. These objects travel at immense speeds, causing them to heat up and burn in a spectacular display known as a fireball or bolide. For centuries, people observing these bright events have reported a strange, faint sound that arrives simultaneously with the light. Although this claim was historically met with widespread scientific dismissal, modern research confirms the perception of simultaneous sound has a genuine physical basis, involving electromagnetic interaction rather than conventional sound waves.
The Acoustic Paradox
The primary reason for initial skepticism about hearing a meteor is the vast distance at which these events occur. Most fireballs become visible and burn out in the upper atmosphere, typically at altitudes between 50 and 70 miles above the ground. If the meteor produced an ordinary sound wave, such as a large sonic boom, the noise would have to travel this entire distance to reach an observer on the surface.
Sound moves relatively slowly through the air, traveling about one mile every 4.7 seconds. For a meteor exploding 60 miles up, any physically generated sound would take nearly five minutes to arrive. This significant time gap between seeing the meteor and hearing a delayed boom is expected. However, it creates a paradox for observers who report hearing a sound simultaneously with the visual streak, as this sound cannot be explained by standard atmospheric physics.
The True Mechanism: Electrophonic Waves
The correct explanation for the simultaneous sound bypasses the slow speed of sound entirely by involving electromagnetic energy. As a large, fast-moving meteoroid plunges into the atmosphere, it undergoes extreme deceleration and ablation, generating a highly ionized plasma trail behind the meteor.
This turbulent plasma trail interacts dynamically with the Earth’s natural magnetic field, converting the meteor’s kinetic energy into powerful electromagnetic radiation. This energy is emitted primarily in the Extremely Low Frequency (ELF) and Very Low Frequency (VLF) range (100 Hertz and 50 kilohertz). Since electromagnetic waves travel at the speed of light, they arrive at the observer almost instantaneously with the visual flash. This immediate arrival of the VLF wave solves the acoustic paradox, establishing a mechanism for concurrent sound perception.
How the Sound Manifests Locally
Even though the VLF waves arrive instantly, they are invisible radio waves that cannot be heard directly by the human ear. The final step in this process is the transduction, or conversion, of these electromagnetic waves into audible sound at the observer’s location.
The VLF waves induce weak electric currents in objects that are electrically conductive or semi-conductive, which act as a local antenna. These objects, positioned close to the observer, begin to vibrate minutely as they interact with the incoming electromagnetic field. This localized effect generates a pressure wave in the air directly next to the observer’s ear, which is perceived as a faint hissing, crackling, or popping noise.
Historical Accounts and Modern Confirmation
Reports of simultaneous meteor sounds date back centuries, with anecdotal accounts found in ancient Chinese and Arab chronicles. In the early 18th century, astronomer Edmund Halley famously dismissed observer reports of hissing noises from a bright bolide as mere imagination. This general scientific dismissal persisted for decades, as the instantaneous sound seemed to defy the known physics of sound propagation.
The electrophonic sound theory gained prominence in the 1980s through the work of physicist Colin Keay, who provided a theoretical framework for VLF generation. The theory was validated in the late 1990s and early 2000s when researchers used specialized radio receivers and microphones. These instruments successfully recorded VLF electromagnetic pulses and simultaneous audible sounds during major meteor showers, such as the Leonids. Recordings confirmed that only the brightest fireballs, typically exceeding a visual magnitude of -9, are powerful enough to generate the sustained VLF waves necessary to produce this localized sound effect.