Earth is the only planet that is known to sustain life in our solar system
One of the factors that make our planet habitable is its atmosphere
Atmosphere
The blanket or envelope of gases surrounding the earth
Atmosphere
Keeps us warm
Gives us oxygen to breathe
Where weather happens
Keeps the overall temperature of the earth fairly steady especially between night and day
Gases in the atmosphere
Nitrogen (78%)
Oxygen (21%)
Other trace gases (1%)
Trace gases
Carbon dioxide
Inert gases
Hydrogen
Methane
Ozone
Layers of the atmosphere
Troposphere
Stratosphere
Mesosphere
Thermosphere
Exosphere
Troposphere
Lowest layer, where we live, 75% of total mass, 99% of water
Troposphere
Where wind, clouds and water vapor are found
Where weather phenomena takes place
Air is constantly moving, causing turbulence for aircraft
Stratosphere
Air flow is more stable than troposphere, temperature increases with altitude, contains ozone layer
Ozone layer
Protects us from harmful ultraviolet rays from the sun
Mesosphere
Temperature decreases with altitude, coldest layer, burns up most meteors and asteroids before reaching Earth's surface
If there was no mesosphere, meteors and asteroids would directly hit our planet, causing disasters
Thermosphere
Closer to the sun, absorbs a large amount of solar radiation, temperature increases tremendously, where the International Space Station and space shuttles orbit
Ionosphere
Ion-rich region found within the thermosphere, where auroras are seen
Exosphere
Last layer, merges into outer space, temperature varies from very hot to very cold, ideal for placing artificial satellites as there is little friction
