  Stars are transparent to the passage of primordial black holes (PBHs) and
serve as seismic detectors for such objects. The gravitational field of a PBH
squeezes a star and causes it to ring acoustically. We calculate the seismic
signature of a PBH passing through the Sun. The background for this signal is
the observed spectrum of solar oscillations excited by supersonic turbulence.
We predict that PBHs more massive than 10^21 g (comparable in mass to an
asteroid) are detectable by existing solar observatories. The oscillations
excited by PBHs peak at large scales and high frequencies, making them
potentially detectable in other stars. The discovery of PBHs would have
profound implications for cosmology and high-energy physics.
