Tyrannosaurus rex looms in recent history as likely the most famous dinosaur that ever lived. The Jurassic Park movies pumped new life into its image as a savage predator. But how much of this is Hollywood hype and how much reflects science?

James Benson Irwin (March 17, 1930–August 8, 1991), an American astronaut and scientist, was lunar module pilot for Apollo 15 on the fourth human lunar landing and was the eighth person to walk on the moon.¹