Killer Rocks from Outer Space: Asteroids, Comets, and Meteorites(Discovery)

By Steven Koppes

Sixty-five million years ago, the dinosaurs suddenly became extinct.Scientists primarily believe that their disappearance was due to a huge cosmic bomb--a comet or asteroid approximately six miles in diameter that blasted into the surface of the planet.Throughout the past century, researchers have identified more than a hundred impact sites around the world created over the past three hundred and fifty million years.They believe that another cosmic bomb is inevitable and that when it hits Earth, there will be few survivors.To prevent that from happening, astronomers are constantly searching the galaxy for asteroids and comets.They study them in the hopes that they could one day prevent them from destroying humankind.

• Format: Unknown Binding
• Language: English
• ISBN: 0822528614
• ISBN13: 9780822528616
• Release Date: January 1
• Publisher: Lerner Publishing Group
• Length: 112 Pages
• Weight: 1.05 lbs.
• Dimensions: 8.8" x 0.5" x 7.5"
• Age Range: 11 to 17 years
• Grade Range: Grades 6 to 12