Mysterious fireball reported over South Carolina, Georgia and Tennessee in the US

From Georgia to South Carolina and Tennessee, a mysterious flaming object could be seen streaking the sky early in the afternoon of June 26, leaving a trail of exhaust in its wake, and then dramatically plunking towards the ground.

Scientists, meteorologists, and even law enforcement officials in those states were working to figure out what had caught the attention of drivers and observers in such a wide swath of the South. The sightings prompted hundreds of calls to the authorities.

Whatever it was, a small object that may have broken off from it punched through the roof of a home just south of Atlanta, cracking the home’s laminate flooring.

Hours later, after widespread speculation, Nasa declared that the object in question was a meteor barrelling through the earth’s atmosphere at over 48,000kmh.

Mr Bill Cooke, the chief of Nasa’s Meteoroid Environments Office at the agency’s Marshall Space Flight Centre in Huntsville, Alabama, said the meteor was about 90cm in diameter and weighed over a tonne.

It was first seen 77km above the town of Oxford, Georgia, Mr Cooke said. It began to disintegrate 43.5km over West Forest, Georgia, “unleashing an energy of about 20 tonnes of TNT”, he said in a statement.

“The resulting pressure wave propagated to the ground, creating booms heard by many in that area,” he said.

The fireball that caught the attention of people across the region was from the meteor fragmenting in the sky.

Earlier in the day, there were reports spreading on social media of fireballs streaking across the sky, windows rattling in their frames and loud noises that startled residents.

Experts, including meteorologists, were trying to piece together what had fallen through the atmosphere.

Mr Keith Stellman, the meteorologist-in-charge at the National Weather Service in Atlanta, said at the time that the authorities could not yet confirm if it was indeed a piece of a meteor or “space junk or a broken piece of satellite”, but they collected it as evidence from the floor of a home in McDonough, about 48km south of the city.

“It happened around the same time we started getting reports of a possible earthquake and some people saying they were hearing thunder,” Mr Stellman said.

There were about 130 reports of fireball sightings in 20 states, according to the American Meteor Society, beginning just after noon. It was not clear how many of those were related to the event seen on videos circulating on June 26.

“It looks to be a ‘daytime fireball’ that caused a sonic boom,” said Mr Mike Hankey, the operations manager at the American Meteor Society. “This is usually indicative of a meteorite dropping a fireball, but not always.”

A fireball is a very bright meteor – generally brighter than the planet Venus – in the morning or evening sky, according to the American Meteor Society.

“If they’re bright enough and far away enough from the sky, certainly you can see a fireball,” said Mr Robert Lunsford of the American Meteor Society, who tracks and verifies fireball reports worldwide. “On a personal level, it’s a once-in-a-lifetime thing, but we might get one per month.”

Fireballs start becoming visible at about 80km altitude, Mr Lunsford said, and they disintegrate at about 40km altitude.

“It takes a really, really big fireball to make it to the ground, and all that’s left are pebbles.”

The American Meteor Society receives an average of 100 reported sightings per day, Mr Lunsford said. About 25 might be of the same object, he said, and the other 75 are of the debris created by that object.

“If they look like they’re close, that’s due to the velocity with which they’re striking the atmosphere,” he said, adding that their range of speed is about 24km to 80km per second.

Artificial objects, like satellites and rockets, are far slower. If an object can be seen for more than five seconds, it is not a meteor, he emphasised.

The weather service office in Charleston, South Carolina, said on its social media page that its satellite-based lightning detection system showed “a streak within cloud-free sky” over the border between North Carolina and Virginia, over Gasburg, Virginia.

The office said the streak was detected between 11.51am (11.51pm Singapore time) and 11.56am local time.

An estimated 40 to 100 tonnes of space material strike earth every day, and most of it is very small particles, according to the European Space Agency. NYTIMES