On a spring day in 2023, a fireball streaked across the Alaska sky.
The event was not clearly captured by satellites or all-sky cameras. However, low-frequency sound waves (infrasound) from the meteoroid were recorded by a dense network of seismic and infrasound sensors used for earthquake and volcano monitoring.
Reconstruction Method
A team led by Sandia National Laboratories analyzed signals from 57 instruments — including 37 seismic stations, 16 infrasound sensors, and 4 infrasound arrays — some located up to 360 miles away. They combined these data with weather radar and publicly shared dashcam and security camera videos to reconstruct the meteoroid's atmospheric path, breakup location, and probable debris fall zone.
Key Findings
- The meteoroid entered the atmosphere at an angle of about 19 degrees.
- Its speed was estimated between 50,000 and 56,000 mph.
- The energy released was equivalent to approximately 38 tons of TNT.
- The object likely originated from the main asteroid belt.
This marks the first known instance of locating meteorite debris on radar guided solely by seismoacoustic data.
Significance for Planetary Defense
The study, published in the Journal of Geophysical Research: Planets and funded by the Defense Threat Reduction Agency, demonstrates that infrasound and seismic data can provide rapid post-event characterization even when optical coverage is sparse. This technique can help determine debris fall zones, origin, and potential hazards.
Video Contribution
Citizen scientists provided dashcam and security camera footage. The team used calibration images of the night sky to determine viewing geometry, which helped refine the reconstruction of the meteoroid's path.
Radar Debris Detection
Based on the sensor-based reconstruction, Doppler weather radar was used to identify signatures of falling debris. This is the first known instance of locating meteorite debris on radar guided solely by seismoacoustic data.