Robert Zubrin | Pioneer Astronautics, 11111 W. 8th Ave. unit A, Lakewood, CO 80215, USA
Abstract Excerpt
“It is shown that a mechanism involving only random motion of the sun with respect to the surrounding star field can account for the ∼1 per 25 Myr characteristic frequency of large cometary impacts on Earth. In the proposed mechanism, the sun travels through the Oort Cloud of an encounter star, most typically a Type M dwarf, while the dwarf flies through the Oort cloud of our Sun. As a result, Oort Cloud objects from our Solar System are precipitated in large numbers to impact planets in the dwarf star system, while the dwarf’s Oort Cloud objects are destabilized to impact planets in our Solar System.”