The theories lit up the internet: An earthquake must have caused a prolonged boom that shook homes Sunday morning in New Hampshire and at least one neighboring state.
Some hypothesized that the puzzling disturbance might have been the sound of an aircraft breaking the sound barrier. Both scenarios were quickly discounted.
Now some meteorologists think they can explain the mystery.
Satellite imagery suggests that a meteor might have exploded in the atmosphere over New Hampshire, according to those meteorologists, who say that explanation is not at all far out.
This time of year, they pointed out, is known for intense meteor showers: the Draconids that peaked two days earlier and the Orionids that continue until November. The fireballs that explode in a bright terminal flash, often with visible fragmentation, are known as bolides, according to the American Meteor Society.
“Sure enough, there was a little blip there right around the time that folks started calling and reporting about the sound,” Greg Cornwell, a meteorologist for the National Weather Service in Gray, Maine, the forecast office for New Hampshire, said Tuesday.
Cornwell said that the blip was detected by a geostationary weather satellite, known as GOES-16, that was used by the National Oceanic and Atmospheric Administration and NASA. He and his colleagues reviewed the satellite feed from Sunday morning. On it, a blue dot flashed over southern New Hampshire around 11:21 a.m.
“It wasn’t until the next morning when we were like, ‘Well, I wonder what the cause was?’” he said. “There was a lot discussion from the public.”
The satellite has an advanced system for detecting lightning, but there were no thunderstorms in the area Sunday morning, Cornwell said.
“Now there have been cases where these sort of exploding fireballs or bolides will cause a false positive,” he said. “It showed up in the data, and it’s kind of a hunch.”
Doug Chappel, a mechanical engineer from Hillsborough, New Hampshire, which is about 25 miles west of Concord, New Hampshire, said Tuesday that he was hiking with his family in the Fox Forest when he heard the boom.
“I’m a Cold War kid,” Chappel said. “If I wound up finding out that Boston and New York had been incinerated by an H-bomb, I wouldn’t have been surprised.”
Chappel said his family used to live in Florida and had been accustomed to hearing the sound of the space shuttle launching and returning to Earth. What he experienced Sunday — extended thunder-like peals caught on home security camera footage provided by Chappel — was something different.
“It lasted too long to be a sonic boom signature,” Chappel said.
Paul D. Raymond Jr., a strategic communications administrator for the New Hampshire Department of Safety, said in an email Tuesday that the agency’s partners at the weather service were eyeing a meteor as the source of the disturbance and investigating.
NASA did not immediately comment Tuesday.
In the entire Northeast, there have been no earthquakes in the past seven days, according to the National Earthquake Information Center, which is part of the U.S. Geological Survey and maintains a map of seismic events.
A spokesperson for the Federal Aviation Administration said Tuesday that the agency had no reports related to any aircraft noise in the area, while local officials have said that the sound did not come from a military aircraft.
Mike Wankum, a meteorologist for the television station WCVB, an ABC affiliate for Boston, reached a similar conclusion as forecasters at the weather service about a meteor explosion possibly causing the boom.
“Now it has to explode 30 miles or less to get that sonic boom that’s out there,” Wankum said during a broadcast Monday. “And it can take a minute and a half to four minutes to get that rumble to kind of work its way through. But that’s probably what you were hearing.”