Organic globules found in a meteorite that slammed into Canada's Tagish Lake may be older than our sun, a new study says.
The ancient materials could offer a glimpse into the solar system's planet-building past and may even provide clues to how life on Earth first arose.
"We don't really look at this research as telling us something about [the meteorite itself] as much as telling us something about the origins of the solar system," said Scott Messenger of the NASA Johnson Space Center in Houston, Texas.
Most of the meteorite's material is about the same age as our solar system—about 4.5 billion years—and was likely formed at the same time (tour a virtual solar system).
But the microscopic organic globules that make up about one-tenth of one percent of the object appear to be far older.
In a study appearing in tomorrow's issue of the journal Science, Messenger and colleagues report that isotopic anomalies in the globules suggest that they formed in very cold conditions—near absolute zero.
"What's really striking about this is that these globules clearly could not possibly have formed where [the meteorite] itself formed," Messenger said.
"Under those extreme conditions the air that you'd breathe would be solid ice. You would never find those conditions in the asteroid belt or anywhere close to the sun."
Cold Origins
The Tagish Lake meteorite flashed across Earth's northern sky in January 2000.
Most of the object burned up in the atmosphere, but pieces of it crashed in Canada's frozen, sparsely populated Yukon Territory and northern British Columbia (map of Canada).
"It's the lowest density meteorite that's ever been studied," said Peter Brown, a meteor expert and professor at the University of Western Ontario in Canada.
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