When a bright fireball streaked across the sky over Alaska last spring, scientists anticipated that cameras and satellites would precisely track its origin and potential landing sites. However, many of these observational tools missed crucial details. Fortunately, the fireball left behind another valuable clue—powerful low-frequency sound waves that traveled hundreds of miles through the atmosphere.
By analyzing these sounds alongside subtle ground vibrations, weather radar data, and videos shared by the public, researchers reconstructed the fireball’s trajectory. Their findings, published in the Journal of Geophysical Research: Planets, demonstrate that “listening” to a meteor can be just as effective as observing it visually.
The investigation started on the day the fireball appeared. Logan Scamfer, then a research assistant at the University of Alaska Fairbanks, noticed unusual signals in data collected by earthquake monitoring stations. Initially, these signals didn’t resemble typical earthquake patterns. As he examined data from multiple monitoring stations across Alaska, he saw the same unusual pattern recurring.
He also detected a distinct “N-wave,” a unique sound pattern often produced by shockwaves from fast-moving objects. This led him to suspect that a meteor had entered Earth’s atmosphere. News reports later confirmed many eyewitnesses had seen a bright fireball cross the sky.
A month afterward, Scamfer began an internship at Sandia National Laboratories, working alongside physicist Elizabeth Silber, an expert in studying meteors via infrasound—sound waves of very low frequency that are inaudible to humans but can travel vast distances. Since cameras and satellites didn’t fully capture the event, the team relied heavily on the sound waves and ground vibrations recorded by various sensors.
Alaska proved to be an ideal location for such work, due to its extensive network of seismic and infrasound sensors used mainly for monitoring earthquakes and volcanic activity. These instruments also detected the pressure waves generated by the meteoroid traveling at hypersonic speeds through the atmosphere.
In total, 57 sensors recorded signals from the fireball, including earthquake and infrasound stations, some detecting the event from as far as 580 kilometers away. By analyzing the timing of these signals, scientists mapped the meteoroid’s path, pinpointed where it disintegrated, and estimated the probable crash site for meteorite fragments. This information was shared with a NASA scientist, who utilized Doppler weather radar to locate the falling debris cloud.
The team also corroborated their findings with dashcam and security camera footage provided by citizen scientists, enhancing the accuracy of their reconstruction. They estimate the meteoroid entered the atmosphere at roughly 19 degrees and traveled between 80,000 and 90,000 kilometers per hour. The energy released from the explosion was equivalent to about 38 tons of TNT, and the object probably originated from the asteroid belt between Mars and Jupiter.
This study represents the first successful effort to locate meteorite debris on weather radar primarily using sound and seismic data. This innovative method offers a promising tool for planetary defense, especially when fireballs occur during daylight hours or in regions inaccessible to cameras.
By integrating sound, seismic signals, radar data, and citizen videos, scientists demonstrated that even without clear visual evidence, a fireball’s story can still be uncovered—if one knows how to listen.
