On a clear June day in Georgia, a blazing fireball suddenly fell out of the sky over the Atlanta metro area. The source of this spectacle was a 1-ton meteor that exploded in mid-air, sending a cherry tomato-sized fragment shooting through the roof of a McDonough home.
Though no one knew it then, this space rock hailed from a time long before Earth had even formed. Using optical and electron microscopes, geologists at the University of Georgia analyzed 0.8 ounces (23 grams) of fragments recovered from the piece that ripped through the house on June 26. Their study revealed that this meteor was likely over 4.56 billion years old. That’s 20 million years older than our planet.
“This particular meteor that entered the atmosphere has a long history before it made it to the ground of McDonough, and in order to totally understand that, we actually have to examine what the rock is and determine what group of asteroids it belongs to,” Scott Harris, a University of Georgia geology researcher, said in a release.
Harris and his colleagues extrapolated the meteor’s age by classifying the recovered fragments. The composition of the debris indicated it came from a low-metal ordinary chondrite, a group of asteroids in the main belt between Mars and Jupiter. Experts believe they stem from a breakup of a much larger asteroid that occurred about 470 million years ago, Harris explained. As these meteors orbit the Sun, they occasionally cross through Earth’s orbit, he said.
That’s what allowed this interloper to pierce through Earth’s atmosphere and ultimately an unsuspecting Georgian’s home. According to the UGA release, researchers clocked the meteor entering the atmosphere at cosmic velocity, which is faster than the speed of sound. Indeed, people widely reported sonic booms along the ground track of the fireball, which traveled from northeast to southwest to the site of its crash landing, NASA’s Meteoroid Environment Office states.
The 3-foot-wide (1-meter-wide) meteor disintegrated—or blew up—27 miles above Wake Forest, Georgia, unleashing a blast of energy equivalent to roughly 20 tons of TNT, according to NASA’s All Sky Fireball Network. When a pebble-sized fragment punched through a McDonough man’s roof, Harris suspects he heard three things at once.
“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,” he said. “There was enough energy when it hit the floor that it pulverized part of the material down to literal dust fragments. The resident told Harris he’s still finding space dust around his living room, according to the release.
The cherry tomato-sized meteorite, officially named the McDonough meteorite, is the 27th recovered in Georgia in history and only the sixth documented fall. “This is something that used to be expected once every few decades and not multiple times within 20 years,” Harris said. “Modern technology in addition to an attentive public is going to help us recover more and more meteorites.”
The McDonough meteorite will remain at UGA for further analysis, and Harris plans to publish a paper on its composition, speed, and dynamics. These details will help scientists understand the potential threat of larger and more dangerous asteroid impacts. “One day there will be an opportunity, and we never know when it’s going to be, for something large to hit and create a catastrophic situation. If we can guard against that, we want to,” Harris said.
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