Don Brownlee Pluto Quotations

There are two major possibilities. One that they formed in the innermost, hotter-most regions of our solar system when the sun and planets were forming, and they were thrown out -- all the way out to the Pluto region of the solar system. The other possibility is they were formed around other stars, in hot regions around other stars.

This comet formed at very edge of the solar system ... out by pluto ... and spent all its lifetime out there until recently it came into the inner part of the solar system, where we could sample it.