Possible constraints on asteroid-mass primordial black holes from Solar system cratering

ABSTRACT Due to their novel cratering mechanism, primordial black holes (PBHs) in the asteroid mass window of about $10^{17}$ to $10^{19}$ g can produce surface features on Solar system bodies that are distinguishable from traditional impact craters. High-resolution surface scans of old cratered Solar system bodies therefore provide a way to test compact dark matter candidates like PBHs. In this work, we calculate the flux of PBHs across three targets: the Moon, Mercury, and Ganymede. We consider PBHs from both the galactic halo and thick dark disc, and include modulation due to annual and galactic orbits, gravitational focusing, and the vertical oscillation of the Solar system. We show that non-detection of a PBH crater on all three of these bodies has the potential to constrain PBHs as dark matter near the evaporation limit, potentially improving current constraints by up to about an order of magnitude, or roughly $10^{18}$ g.