Seismic Networks Map Space Debris Trajectories During Atmospheric Reentry

Earthquake monitoring networks, designed to detect tectonic tremors, are now being repurposed to track the fiery descent of space debris as it plummets through the atmosphere. Seismometers can detect sonic booms from falling objects, enabling real-time tracking of reentry paths.

This method was tested during the 2024 reentry of China's Shenzhou-15 spacecraft module, which traveled at Mach 25-30 before breaking apart at an altitude determined via seismic data.

Benjamin Fernando, lead author of the study, described the growing frequency of reentries as "a growing problem, and it's going to keep getting worse." Seismometers in southern California traced the Shenzhou-15 debris' trajectory 25 miles north of U.S. Space Command's predicted path.

The technique complements radar-based tracking by providing post-reentry verification of debris fragmentation, altitude, and ground impact locations.

"If you want to help, it matters whether you figure out where it has fallen quickly... in 100 seconds rather than 100 days," Fernando noted. The study, published January 22, 2026, in Science (DOI: 10.1126/science.adz4676), demonstrates how seismic networks can enhance debris tracking capabilities.

The team emphasized that this approach offers critical advantages for locating debris fields, particularly when dealing with objects carrying radioactive materials.