How Sound Helped Find a Space Rock Over Alaska ⚡ экспресс
On April 24, 2025, a bright fireball streaked across southern Alaska. A dense network of seismometers and infrasound sensors (which pick up low-frequency sound) recorded not only the explosion itself, but also dozens of distinct signals from the object breaking apart. Weather radar data helped pinpoint the meteorite fall area. Calculations revealed: entry speed 25.3 km/s, energy roughly 38 tons of TNT, size about 0.7 meters. This event in the subpolar region proved that ground-based acoustic and seismic networks can provide reference-quality trajectories where satellites fall short, merging planetary defense and space debris tracking.
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.