Alien comets were stolen by Sun 4.5bn yrs ago
Washington: Computer simulations in a new study have shown that the early Sun could have stolen comets from neighboring newborn stars 4.5 billion years ago.
Hal Levinson of the Southwest Research Institute (SWRI) in Boulder, Colorado conducted the study, reports Discovery News.
At a distance of roughly six trillion miles from the sun an unknown number of ancient comet nuclei-each just a few miles across-drift at temperatures near absolute zero.
This hypothetical region was named the Oort cloud after mid-20th century Dutch astronomer Jan Oort, who first proposed such a twilight region to explain what seemed to be a hidden reservoir of comets.
The primeval deep freezer may contain comets that were gravitationally snatched from other stars.
Conventional wisdom has been that comets accompanied our own solar system's planetary formation and then got gravitationally booted out to huge distances, like storing junk in the attic. But this kind of mayhem was happing around neighbouring star systems too.
Therefore, interstellar space got cluttered with a snowstorm of comets orphaned from their birthing star.
Levinson's model estimates that there should be 400 billion comets out there that are loosely bound to the sun. But in those simulations where the comets only originate in the newborn solar system, the predicted population is a paltry 6 billion-one for nearly every person now living on Earth.
Levinson and his team say that the ''alien comet'' idea is bolstered by observations that found comets with very long orbital periods.
If this idea is correct, that comets could give us not just domestic chemistry of the primeval solar system, but imported chemical samples of the environment around those stars that where born along with the sun.