How Sound Helped Find a Space Rock Over Alaska ⚡ экспресс
On April 24, 2025, a bright fireball over southern Alaska was tracked by a seismoacoustic network of 37 seismometers, 16 infrasound sensors, and 4 infrasound arrays, yielding 30 ballistic and numerous fragmentation signals. Acoustic reconstruction combined with fragmentation localization allowed identification of the meteorite trail on weather radar. The refined endpoint agrees well with independent optical solution from video. Entry parameters: speed 25.3 km/s, angle 19°, energy ~38 tons TNT, diameter ~0.7 m (chondrite), orbit likely L-chondrite. This subarctic case demonstrates how dense ground networks close gaps in space monitoring. Multi-sensor integration delivered a reference-quality trajectory, blurring the line between asteroid defense and analysis of artificial entries.
On April 24, 2025, a celestial drum boomed over Alaska. Sunlight outshone the flash, and satellites missed the meteor. But the earth and air acted like a giant percussion instrument: dozens of ground microphones picked up a low rumble, and vibration sensors detected tremors. This provided a precise 'melody' of its flight.
The shockwave from the fast rock (25 km/s) made the air resonate like a membrane, and the ground vibrate like a drum body. A network of sensors, originally designed for monitoring nuclear tests, helped calculate the size (70 cm) and energy (38 tons of TNT) of the uninvited guest. It turned out to be an ordinary stony chondrite of type L.
The method is cheap and unafraid of polar day. Now ground-based 'ears' will become a reliable complement to satellite 'eyes' for protection against cosmic intruders.
🎯 The meteor left a whopping 30 shockwaves—like throwing one stone into water sends out dozens of ripples, but here the ripples also traveled through the earth's depths.