  There appear to be three challenges that any theory of dark matter must face:
(i) why is $\Omega_{DM}$ of the same order as $\Omega_{Baryons}$ ? (ii) what
are the near solar mass objects ($\sim 0.5 M_{\odot}$) observed by the MACHO
microlensing project ? and (iii) understanding the shallow core density profile
of the halos of dwarf as well as low surface brightness galaxies. The popular
cold dark matter candidates, the SUSY LSP and the axion fail to meet these
challenges. We argue that in the mirror model suggested recently to explain the
neutrino anomalies, the mirror baryons being 15-20 times heavier than familiar
baryons, can play the role of the cold dark matter and provide reasonable
explanation of all three above properties without extra assumptions.
