  Dark matter particles can form halos gravitationally bound to massive
astrophysical objects. The Earth could have such a halo where depending on the
particle mass, the halo either extends beyond the surface or is confined to the
Earth's interior. We consider the possibility that if dark matter particles are
coupled to neutrinos, then neutrino oscillations can be used to probe the
Earth's dark matter halo. In particular, atmospheric neutrinos traversing the
Earth can be sensitive to a small size, interior halo, inaccessible by other
means. Depending on the halo mass and neutrino energy, constraints on the dark
matter-neutrino couplings are obtained from the halo corrections to the
neutrino oscillations.
