Helium-3 from Asteroids? (Oh my)

Sources of helium-3:
-- asteroids and their associated dust particles
-- dormant comets
-- moon
-- produced from tritium (Hydrogen 3) degradation using particle
accelerators.

Asteroids:

"The researchers know these particular Buckyballs are
extraterrestrial because the noble gases trapped inside have an
unusual ratio of isotopes. For instance, terrestrial helium is
mostly helium-4 and contains only a small amount of helium-3, while
extraterrestrial helium - the kind found in these fullerenes - is
mostly helium-3. .. These things form in carbon stars. That's what's
exciting about finding fullerenes as a tracer," Becker said. The
extreme temperatures and gas pressures in carbon stars are perhaps
the only way extraterrestrial noble gases could be forced inside a
fullerene, she said. These gas-laden fullerenes were formed outside
the Solar System, and their concentration at the Permian-Triassic
boundary means they were delivered by a comet or asteroid."
http://www.washington.edu/newsroom/news/2001archive/02-
01archive/k022201.html

".. The matter involved detecting the helium isotope known as 3He,
which is rare on Earth but common in extraterrestrial materials. 3He
is very abundant in the sun, and some of it is ejected from the sun
as solar wind throughout the solar system. The helium is easily
picked up and carried along by extraterrestrial objects such as
asteroids and comets and their associated dust particles. .."
http://pr.caltech.edu/media/lead/052198KF.html