"Seismic Sensors Capture Sonic Boom Rattling Montana and Yellowstone"

A loud boom was heard by hundreds of people in southwest Montana, Idaho, and Utah, and was also recorded on seismic sensors in western Montana. The boom coincided with reports of a fireball in the sky, leading experts to believe it was either a meteor or a large piece of space junk entering the atmosphere. Sonic events like this are relatively rare compared to daily earthquakes.