Recently reported observations of the Bullet Cluster of galaxies (see http://www.nasa.gov/centers/marshall/news/news/releases/2006/06-096.html ) claim proof that what I'll call Exotic Dark Matter (EDM) exists. Previously the most direct evidence for lots of some sort of Dark Matter (DM) was, as far as I know, the observations of Zwicky, Vera Rubin and others on galaxy rotation curves, taken together with excessive galaxy velocities in virialised clusters. I know that these observations show that there is too much DM (about 20% of amount needed to flatten the universe) to be accounted for by calculations of nucleosynthesis that match observed cosmic element abundances. What I don't know is whether these calculations are the only justification for the very bold assumption that the extra DM is EDM of a kind otherwise unknown to physics. Is this indeed so? A possibility that seems to have been rejected on this account is that the unobserved DM in the universe is planetary sytems, Pluto-like objects and stuff like the postulated Oort cloud on the fringes of our system, brown and black dwarfs and possibly shoals of isolated black holes -- i.e. that it is miscellaneous Big Lumps of Junk (BLJ) that we can't detect. Such BLJ would be unscattered as it moved through hot gas, like the recently observed DM in the Bullet Cluster. I also don't know if there is any evidence (say from tiny deviations of Keplerian orbital speeds of outer planets) for the existence of either the Oort cloud or a halo of BLJ in deep space beyond the solar system. Does anybody know for sure that there are not enough BLJ out there to account for the gravitationally observed DM?