A loud boom and a wave of ground-shaking that startled residents across eastern Massachusetts on Saturday afternoon was caused by a meteor fireball, NASA confirmed, putting a definitive cause to an event that had set off a flurry of reports of explosions, earthquakes and sonic booms across the region. The agency said the object streaked over the state at around 2:06 p.m. and released a blast of energy equivalent to an estimated 300 tons of TNT.
The fireball, what scientists call a bolide, was travelling at roughly 75,000 miles per hour when it tore through the atmosphere, NASA said. It appears to have fragmented at an altitude of about 40 miles over the area straddling extreme northeastern Massachusetts and southeastern New Hampshire, the point at which the pressure of the descent overwhelmed the rock and produced the energy release that people heard and felt at ground level.
Crucially, NASA said the daytime event was a natural one — "a natural object and not a re-entry of space debris or a satellite" — and that it was not associated with any active meteor shower. That distinction matters because re-entering rocket bodies and defunct satellites produce similar light and sound, and ruling them out points to a chance encounter with a stray piece of the solar system rather than the return of something humans had launched.
The agency traced the object's path to a meteorite fall in the middle of Cape Cod Bay, estimating that any surviving fragments landed in water about 100 feet deep. That placement all but rules out a recovery of the meteorites, which would otherwise be prized by collectors and researchers, but it also meant the fall posed no danger to people or property on the ground.
Reports had poured in from across the region in the minutes after the event, with residents from the Boston area to neighbouring states describing a window-rattling boom and a brief shudder that many initially mistook for an earthquake or an explosion. Local emergency lines fielded calls, and meteorologists and seismologists were quickly drawn in before NASA's analysis pinned the cause on the sky rather than the ground.
Daytime fireballs bright and energetic enough to be heard as well as seen are relatively uncommon, which is part of why the event generated such widespread alarm before its origin was understood. With the object accounted for and its fragments resting at the bottom of Cape Cod Bay, what remained was a regional shared memory of a few disorienting seconds and a reminder of how often small pieces of space quietly meet the Earth.