UFO'S

Here are four more ticktock volumes in a brand new series for young adult readers. This imaginative series looks at great mysteries of the past that can be explained by science today. It also covers more recent events, many of which remain unexplained. These books tell the stories, show photographic evidence, discuss theories -- and balance the account with "Professor Skeptic", who offers opinions and provides explanations that account for both hoaxes and entirely natural phenomena. Are they optical illusions caused by swamp gas, or are they visitors from distant planets? This volume recounts the famous New Mexico sightings of "flying saucers", along with many others.