A fireball stretched over a large swath of the East Coast on Tuesday night and gave off a loud “sonic boom,” experts said.
More than 280 reports came into the American Meteor Society from those who said they saw it. The fireball was reported by many in Ontario, experts said, but the meteor tracking group said it also received reports from New York, Pennsylvania, New Jersey, Delaware, Michigan, Maryland, the District and Virginia.
The fact that there were so many reports of people seeing it ranks the fireball as one of the “top 10 events of the year” in terms of the number of received reports, according to Mike Hankey, operations manager for the American Meteor Society.
One reason so many people saw it, he said, is that it happened around 10:30 p.m., when people were still out and about, he said.
“What struck me is that people from Canada to Southern Maryland saw it,” Hankey said. “That means it was pretty bright.”
Tuesday night’s fireball, Hankey said, included reports of people hearing a “sonic boom,” which are typically heard within a 50-mile radius of a fireball sighting. Some of the reports, he said, came in from parts of north and central Pennsylvania.
“To have that echoing sound means it has to get pretty close to the surface,” Hankey said. “It penetrated the Earth’s atmosphere deep enough to create a sonic boom.”
That, he said, “makes it stand out.”
His group tracks thousands of fireball and meteor sightings each year. Fewer than 10 a year are seen and heard.
Still, it isn’t clear what the fireball was. Hankey said it was unlikely that it was “space trash,” given the way it was traveling.
The more likely scenarios, he said, are that it was an asteroid or a piece of a comet. Comets are made of ice, and they vaporize. But an asteroid — and especially one that has a sonic boom associated with it — could end up as meteorites, or small rocks on the ground.
Hankey said that typically when meteorites fall from the sky, they melt away, but if it “gets deep enough and you hear a sonic boom, maybe something survived and fell to the surface.”
He said his group has not received any reports of people saying they saw parts of a meteorite on the ground.