Layers
Layers of gases surrounding Earth's surface make up the atmosphere. Earth's atmosphere is made up of 4 main layers:
- Troposphere
- Stratosphere
- Mesosphere
- Thermosphere
Troposphere
- The Troposphere is the lowest layer of the atmosphere.
- The Troposphere stretches from 0-12 km.
- All of Earth's weather occurs in this layer.
- Even though it is the shallowest layer, it contains almost all of the mass of the atmosphere.
- As altitude increases in this layer, temperature decreases.
Stratosphere
- The Stratosphere is the second lowest layer of Earth's atmosphere.
- The Stratosphere stretches from 12-50 km.
- This layer contains the ozone layer.
- Temperature increases with altitude. Lower stratosphere is cold, upper is warm.
Mesosphere
- The Mesosphere is the layer above the Stratosphere.
- The Mesosphere stretches from 50-80 km.
- This layer protects Earth's surface from being hit by most meteroids.
Thermosphere
- The Thermosphere is the outermost layer of Earth's atmosphere that extends outward into space.
>"Thermo" means heat.
- The Thermosphere stretches above 80 km.
- Air in this layer can heat up to 1,800 degrees celcius.
Ionosphere and Exosphere
The Thermosphere is divided into two parts: The Ionosphere and the Exosphere
- The Ionosphere is the lower layer of the Thermosphere that begins at 80 km and extends to about 400 km.
- The Exosphere is the lowest layer of the Thermosphere that begins at 400 km and extends outward for thousands of km's.