  Dark matter can be captured by celestial objects and accumulate at their
centers, forming a core of dark matter that can collapse to a small black hole,
provided that the annihilation rate is small or zero. If the nascent black hole
is big enough, it will grow to consume the star or planet. We calculate the
rate of dark matter accumulation in the Sun and Earth, and use their continued
existence to place novel constraints on high mass asymmetric dark matter
interactions. We also identify and detail less destructive signatures: a
newly-formed black hole can be small enough to evaporate via Hawking radiation,
resulting in an anomalous heat flow emanating from Earth, or in a flux of
high-energy neutrinos from the Sun observable at IceCube. The latter signature
is entirely new, and we find that it may cover large regions of parameter space
that are not probed by any other method.
