In late June media speculated that a meteor entering Earth’s atmosphere caused widespread sightings of a celestial fireball during daylight hours across the southeast USA. Scientists have now confirmed space rocks caused the phenomenon, citing as evidence a meteorite they found in a resident’s living room.
As explained by Scott Harris, a researcher in the department of geology at the University of Georgia’s (UGA’s) Franklin College of Arts and Sciences, a homeowner in Atlanta found holes in their roof and a dent in their floor after the June 26 fireball, suggesting something the size of a cherry tomato fell from the sky and into their residence.
“I suspect that he heard three simultaneous things,” Harris opined. “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,” Harris said. “There was enough energy when it hit the floor that it pulverized part of the material down to literal dust fragments.”
Hole in an Atlanta floor caused by the McDonough Meteorite – Click to enlarge
UGA received 23 grams of the 50 recovered from the rock that penetrated the house, and Harris analyzed it using optical and electron microscopy.
“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,” Harris said. Asteroids in that region of space are older than Earth.
The McDonough Meteorite – Click to enlarge
Harris and other scientists who have worked on the rock named it the “McDonough Meteorite”, a name chosen to reflect the Nomenclature Committee of the Meteoritical Society’s convention that space rocks take the name of the location where they land.
NASA estimates that 44,000 tonnes of meteor-matter reach Earth every day. The Australian Museum points out that most of it is dust or very small, and that most falls into the sea. “About 500 meteorites of reasonable size would hit the Earth’s surface every year, of which 150 would fall on dry land, and less than 10 would actually be found,” according to Collection Manager for Mineralogy & Petrology Ross Pogson.
The McDonough Meteorite is therefore rather rare, but UGA’s Harris thinks we may be on the cusp of a golden age in space-rock spotting.
“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.” ®
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