1. Air and Aerodynamics

2. We live at the bottom of an ocean…
an ocean of air. Approximately 500 kilometers deep, this mixture of gases is called the atmosphere. The atmosphere thins out in each higher layer until the gases dissipate in space. There is no distinct boundary between the atmosphere and space, but an imaginary line about 110 kilometers from the surface is where scientists believe the atmosphere meets outer space.

3. THE LAYERS OF THE ATMOSPHERE:
The layers in order from the Earth towards outer space are:
TROPOSPHERE: Earth’s surface to km It is the most dense layer and almost all weather is in this region.
STRATOSPHERE: Above the troposphere to 50km. The ozone layer is in this layer.
MESOSPHERE: Above the stratosphere to 85km. Meteors burn up in this layer.
THERMOSPHERE: Above the mesosphere to 600km. Aurora and satellites occur in this layer.
EXOSPHERE: Above the thermosphere up to km. It is the upper limit of our atmosphere.

4. AIR
Air is made of invisible gases that you cannot smell, taste or touch. The composition of air is approximately: 78% nitrogen, 21% oxygen, 0.93% argon & trace amounts of carbon dioxide, water vapour, neon, helium, krypton, hydrogen, methane and xenon.

5. With the exception of hydrogen, all gas particles are attracted to the Earth by gravity. This explains why our ocean does not float into space!

6. AIR FACTS: moves like water
oxygen, nitrogen, carbon dioxide are necessary to sustain life
has weight
has volume
exerts pressure, wind currents
can be compressed (squeezed)