*Fully revised and updated for the 21st century*The #1 New York Times bestselling author of Astrophysics for People in a Hurry takes readers on an odyssey into the deepest, darkest depth of the universe and back again with his extra-terrestrial tour guide, Merlin. Merlin is a timeless visitor to Earth from the planet Omniscia in the Andromeda galaxy, and he has observed first-hand many of the major scientific events of Earth's history - from the Big Bang to the extinction of the dinosaurs and beyond. In Merlin's Tour of the Universe, Merlin responds to popular questions asked by adults and children alike about the universe and our place within it.All questions are answered with authentic science, infused with wit, wisdom, an occasional rhyme and accompanied by the odd illustration.Merlin's friends include the most important scientific figures and explorers of all time - including da Vinci, Magellan, Newton, Einstein and Hubble, and Merlin's Tour also features playful conversations with these historical luminaries. Based on the first book that Tyson ever published in the 1990s and now fully updated and extended for the twenty-first century, Merlin's Tour of the Universe is a must-read for anyone who wants to know more about how the cosmos works.