Earthquake detectors can accurately track space debris falling to Earth

Scientists have developed a novel method to track space debris reentering Earth’s atmosphere by using existing global earthquake detector networks to monitor the sonic booms generated as debris travels at hypersonic speeds. Space debris, which moves several times faster than sound, creates shockwaves similar to those from supersonic jets. By analyzing data from seismometers activated by these shockwaves, researchers can reconstruct the debris’ trajectory and more accurately estimate its landing location. This approach was demonstrated by tracking debris from China’s Shenzhou-15 spacecraft, which reentered in April 2024, flying at speeds between Mach 25 and 30 and landing about 25 miles north of predictions made by US Space Command radar data. The method, developed by Benjamin Fernando of Johns Hopkins University and Constantinos Charalambous of Imperial College London, addresses the growing challenge of space debris, which poses increasing risks due to the rising number of satellites and payloads in orbit. Traditional radar tracking can have errors of thousands of