The Atmosphere and Beyond

1. The Atmosphere and Beyond Mr. Leslie’s Science Class

2. The Atmosphere • Gases in the Air • Nitrogen – Plants need this to grow. • Oxygen – Living animals need this to breathe • Carbon Dioxide – helps hold heat on Earth Oxygen

3. What are the two main gases? • The two main gases in air are nitrogen and oxygen.

4. Earth’s Blanket • Earth’s blanket is a layer of gases called the atmosphere. The sun heats the Earth, and the atmosphere holds the heat close to Earth’s surface. • The weight of air as it presses down is called air pressure. Your body is used to air pressure, so you do not feel it.

5. Earth’s atmosphere • There are four layers to our atmosphere. • Thermosphere • Mesosphere • Stratosphere • Troposphere- (closest to Earth) Thermosphere

6. Troposphere (closest to Earth) • Earth’s weather occurs in the troposphere. • Weather is the conditions of the atmosphere at a certain place and time.

7. Stratosphere(6 to 30 miles above Earth) • This layer protects a lot of the harmful Sun’s rays from reaching Earth. • Some jet planes fly in the stratosphere. • There is no weather in this layer so the plane ride is nice and smooth.

8. Mesosphere(30 to 50 miles above Earth) • Most meteors burn up when they reach this layer. (shooting stars) • The coldest temperatures in the atmosphere are found here.

9. Thermosphere(50 to 430 miles above Earth) • Space begins at the top of this layer. • Many space shuttles actually travel in Earth’s atmosphere and never reach space.

10. Greenhouse Effect • Heat from the Sun passes through the atmosphere and is reflected from the surface of the Earth. • Gases in the atmosphere trap some of this heat and keep it close to Earth’s surface.