This document provides an overview of comets, predictions of the end of the world, and the alleged "Planet X." It discusses comet composition, past comet and asteroid impacts on Earth, the solar system's scale and amateur astronomy. It examines data from comets Wild 2, Halley and Tempel 1, as well as comet probe missions. The document analyzes the story of Comet Hale-Bopp and its link to an apocalyptic prediction. It also reviews theories about comets, including the standard "dirty snowball" model and alternative "electric comet" theory. Finally, it summarizes the controversy over an alleged companion object photographed near Hale-Bopp by amateur astronomer Chuck Shramek.