In many models, dark matter particles can elastically scatter with nuclei in
planets, causing those particles to become gravitationally bound. While the
energy expected to be released through the subsequent annihilations of dark
matter particles in the interior of the Earth is negligibly small (a few
megawatts in the most optimistic models), larger planets that reside in regions
with higher densities of slow moving dark matter could plausibly capture and
annihilate dark matter at a rate high enough to maintain liquid water on their
surfaces, even in the absence of additional energy from starlight or other
sources. On these rare planets, it may be dark matter rather than light from a
host star that makes it possible for life to emerge, evolve, and survive.Comment: 9 pages, 3 figures, updated calculations with a larger velocity
dispersion for the central portion of the Milky Wa