Residents across the county reported hearing something akin to a sonic boom Thursday night. Lookout reached out to national experts to figure out what happened.
Social media users from Monterey to Marin counties and all over Santa Cruz County reported some strange sights and sounds around 7:30 p.m. Thursday: a white light streaking across the sky in Cupertino, followed by a sound many residents described as a “big boom” or a “sonic boom.”
Speculation on the source of the sound ranged from an earthquake to fireworks, but Robert Lunsford, a volunteer report coordinator with the American Meteor Society (AMS), told Lookout via email that “From the numerous reports and one video we have so far, we are certain that this was a fireball, which is a meteor that is larger and brighter than normal.”
Lunsford said that fireballs are not unusual, but most of the daylight events aren’t visible because they’re obscured by sunlight. Lunsford added that this was most likely “a random event, not associated with any known meteor shower.”
According to AMS, fireballs can cause a sonic boom, which will be heard long after sighting the fireball — up to five minutes — because sound travels slower than light.
Carrie Nugent, a professor of computational astrophysics and planetary science at Olin College of Engineering in Massachusetts, confirmed that the reported sightings and noise were likely caused by a fireball.
“It’s very exciting and special to witness a fireball,” said Nugent via email. “Although the chances of them happening in one specific part of the Earth are very low, fireballs are seen somewhere on the planet with regularity. About 100 tons of space rocks and dust fall on the Earth each day, though most of it is too small to see.”
The size and weight of the meteor along with the question of whether or not it hit the ground remain unclear.
People who witnessed the fireball can submit reports of what they saw to the AMS website, and upload any video they captured so that researchers can get more information. Several witnesses have already submitted sightings to the AMS log, which can be seen here.