“The history and features of the solar system's asteroid-comet belts, along with the gravitational influences of the Moon's mass and early orbital proximity, ensured that Earth would receive sufficient impact events, especially before animals appeared, to salt Earth's crust with rich ore deposits. These ores played a crucial role in the early launch of metallurgy and, more recently, in the development of global, high-technology civilization. On the other hand, major impact events during the human era have been so infrequent as to pose no risk to humanity's survival nor to global civilization.”