description: Millions of years ago, a giant meteorite killed all the dinosaurs. Find out how! Will humans all be killed in the same way? Find out what we can do. Is there life on the planet Mars? Scientists think maybe the answer is yes. Find out why. Get the facts. Got that? Then read a scary story about what might "Doom from Space". Finally use the Word Check to make sure you know your comets from your asteroids!
language: English
title: Comets
titlecomplete: Comets (Trailblazers)
publisher: Ransom