THE ATMOSPHERE

The atmosphere is made up of:

·         Nitrogen (78%)

·         Oxygen (21%)

·         Argon (1%)

·         Traces of water vapor, carbon dioxide, other gases, dust particles, chemicals from the earth.

It becomes thinner with altitude. In other words, the higher you go, the less dense the atmosphere. It becomes very difficult to breath at 3 km. 

HEIGHT ABOVE THE EARTH	NAME OF ATMOSPHERE	DESCRIPTION
10,000 km and above	Exosphere	Mostly consist of hydrogen and helium gas Consist of four zones/layer:
81-10000 km	Thermosphere	Hottest layer. Space station orbits here.
	MESOPAUSE	TRANSISTION ZONE
51-81 km	Mesosphere	Coldest layer (-85O C), meteors ablate here.
	STRATOPAUSE	TRANSISTION ZONE
17-51	Stratosphere	Ozone layer found here. Ozone traps UV light.
	TROPOPAUSE	TRANSISTION ZONE
7-17 km	Troposphere	Most weather occurs here.

Other classifications of the layers of the Atmosphere:

1.       Ionosphere: Extends from upper mesosphere into thermosphere

2.       Homosphere: Lowest 80 km of the atmosphere in which the relative abundance of the permanent gases are constant.

3.       Heterosphere: The high atmostphere where gases are not well mixed, but rather stratified according to their weights.

4.       Magnetosphere: The region of space surrounding the Earth where the dominant magnetic field is the magnetic field of Earth, rather than the magnetic field of interplanetary space.