BERN, Switzerland, Nov. 9 (UPI) -- A new comet formation model suggests 67P/Churyumov-Gerasimenko -- the snowman-shaped space rock explored by the ESA's Rosetta probe -- is much younger than scientists thought, barely a billion years old.
Researchers previously estimated the comet's age at 4.5 billion years, roughly the age of the solar system. Though Comet 67P does boast primordial material, new research suggests it acquired the material fairly recently.
Scientists arrived at their new hypothesis after studying the comet's structural integrity. Their analysis suggests the bridge connecting the comet's two lobes is quite weak.
"We have found that this structure can be destroyed easily, even with low energy collisions," Martin Jutzi, a researcher at the University of Bern, in Switzerland, said in a news release.
Researchers built a model to determine whether such a vulnerable structure could survive the chaos of the solar system for 4.5 billion years. The model's answer: it couldn't.
Its bi-lobe structure is likely a more recent phenomenon, simulations suggest.
"Chury's present shape is the result of the last major impact which probably occurred within the last billion years," Jutzi explained.
The materials that first formed the solar system are, indeed, found in comets.
"So far, it has been assumed that comets are original building blocks -- similar to Lego," said Willy Benz. "Our work shows that the Lego blocks no longer have their original form, but the plastic that they consist of is still the same as in the beginning."