More than 50,000 meteorites have been found on Earth, scientists say, but only one has been documented to have hit a person.
On June 26, when people across several states in the South reported seeing a fireball in daylight, there nearly was a second instance.
Multiple fragments of that meteorite punched through the roof of a home in McDonough, Ga., just south of Atlanta, dented laminate flooring and missed the man living there by 14 feet. Those pieces have now been determined to be older than the Earth itself.
Scott Harris, a planetary geologist at the University of Georgia, examined 23 grams — less than one ounce — of meteorite fragments recovered from a piece the size of a cherry tomato. A fragment left a dent in the floor about twice the size of a quarter.
The meteorite formed 4.56 billion years ago, about 20 million years before the Earth did, according to Mr. Harris’s findings.
“It belongs to a group of asteroids in the main asteroid belt between Mars and Jupiter that we now think we can tie to a breakup of a much larger asteroid about 470 million years ago,” he said in a news release on Friday.
Most space rocks break apart in Earth’s atmosphere. They disintegrate while traveling at tens of thousands of miles per hour. The bright flare that people saw on June 26 was a result of the pressure on the meteorite exceeding its strength.
A meteoroid that survives a trip through the atmosphere and hits the ground is called a meteorite. Less than 5 percent of the original object — between the size of a pebble and a fist — usually hits the ground, NASA scientists say.
But Mr. Harris said that the fragment created a sound and vibration equivalent to a close-range gunshot upon impact.
“I suspect that he heard three simultaneous things,” Mr. Harris said of the person whose home was hit. “One was the collision with his roof, one was a tiny cone of a sonic boom, and a third was it impacting the floor all in the same moment.”
The resident, who was not immediately available for comment on Monday, told Mr. Harris that he was still finding specks of space dust around his living room.
“There was enough energy when it hit the floor that it pulverized part of the material down to literal dust fragments,” Mr. Harris said in the news release.
He added that the meteorite was the 27th recovered in Georgia.
“This is something that used to be expected once every few decades and not multiple times within 20 years,” he said. “Modern technology, in addition to an attentive public, is going to help us recover more and more meteorites.”
Meteorites that fall to Earth comprises some of the original materials that formed planets billions of years ago.
On Nov. 30, 1954, a nine-pound meteorite plunged through the roof of a home in Sylacauga, Ala., bounced off a large radio and struck E.H. Hodges, inflicting painful bruises but causing her no serious injury. That case is believed to be the only documented collision between a meteorite and a human.
More than 70 years later, Mr. Harris said, he and his colleagues were proposing to name the space rock the McDonough Meteorite, for the small city where the space rock plummeted to Earth faster than the speed of sound.