William Napier (astronomer) and Victor Clube in their 1979 Nature Magazine article, 'A Theory of Terrestrial Catstrophism' proposed the idea that gravitational disturbances caused by the Solar System crossing the plane of the Milky Way galaxy are enough to disturb comets in the Oort cloud surrounding the Solar System. This sends comets in towards the inner Solar System, which raises the chance of an impact. According to the hypothesis, this results in the Earth experiencing large impact events about every 30 million years (such as the Cretaceous–Paleogene extinction event).
Over 15 years later, Rampino and Haggerty fancifully re-named Napier and Clube's Theory of Terrestrial Catstrophism after Shiva, the Hindu god of destruction. Though Rampino and Haggerty do not reference Napier and Clube's original 1979 article in Nature Magazine, they do reference Clube and Napier's later paper which demonstrates the requisite gravitational forces. Certainly Rampino was aware of Napier and Clube's much earlier publication, as Rampino and Stothers' letter to Nature Magazine in 1984 references it.