But most of the history of the solar system--this is why the comet is so important--most of the history of this comet was spent out beyond Neptune, out where Pluto is at the very edge of the solar system, what we call the Kuiper belt.

NPR: Stardust Set to Deliver Comet Samples

And there's only a few places like out where Pluto is where these bodies have survived.

NPR: Stardust Set to Deliver Comet Samples