This is the earth.

The earth has 3 parts: land, water and air.

This is the atmosphere.

The atmosphere is the air around the earth. The atmosphere has some oxygen. Animals and people must have oxygen to live.

A long time ago, the earth had no atmosphere. Then plants began growing. Plants helped to make oxygen for air. The atmosphere began to cover the earth.

Explore Space ... Not Drugs!
Hear what astronauts have to say about staying drug-free.
Last modified: Thu Oct 9 13:49:02 PDT 1997