This document summarizes the known characteristics and proposed scientific explanations of ball lightning. Ball lightning is a rare atmospheric phenomenon that appears as a floating, luminous ball during thunderstorms. It varies in size and can last from a second to over a minute. Several hypotheses attempt to explain ball lightning, including that it is composed of vaporized silicon or nano batteries. Witnesses throughout history have reported encounters with ball lightning. While few facts are known, scientists continue to study this unusual phenomenon.