ASTEROID COLLISION: Is a doomsday asteroid mere science fiction'or a terrifying threat to our very existence on Earth? Scientists have long tracked meteors, comets and asteroids as they streak through the galaxy. But are they telling us the truth about the dangers we may face? How many near misses have there been? What about the single asteroid impact that may have caused the extinction of the dinosaur? Could it happen again? One asteroid impact could flatten major cities, poison our air and water, and virtually wreak havoc on Earth. If a life-threatening asteroid were on a collision course with Earth, what could we do? What are the chances of it happening during our lifetime? Is it only a matter of time? Learn the startling facts!--CROP CIRCLES: What's the Secret Message in Crop Circles? Found the world over, these huge and often highly complex designs are etched into field crops just before the harvest. Some believe they are communications from another world; others see them as messages from God. Musicians even translate their design into haunting melodies. While sceptics write crop circles off as the work of pranksters, one question remains: How could hoaxers manage to create numerous crop circles in England and the United States at the same time without being seen? And why have crop circles become more complex over the years? Do they convey some secret message for all of mankind? How do the electromagnetic properties of crop circles affect people, cell phones and scientific instruments? With each new discovery, the mystery and the controversy intensify.