People around the world say they have met beings from outer space. Do these close encounters prove aliens exist? The Into the Unknown series probes the mystery with Do Aliens Visit Earth? The investigation begins with early reports of alien contact and takes readers through decades of unexplained events. Believers present their stories while skeptics seek out the evidence behind the most famous cases. Full-color images and fast facts add to the story. A timeline traces alien abduction's history while a glossary explains important terms. Reading and viewing suggestions point the way for anyone interested in learning more.