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 Post subject: The Atmosphere...earths protector
Unread postPosted: Sat Aug 15, 2009 12:40 pm 
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Joined: Wed Nov 15, 2006 12:48 pm
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Without the atmosphere earth would be nothing but a planet similar to Mars...life as we know it and all it's splenders would not exist.
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It is more than just the air we breathe...it's a buffer that keeps us from being hammered by meteorites, a screen keeping out deadly radiation and allows radio waves to be sent long distances around the planet.
The air that sets all of this into action is composed of five major layers.

The Troposhpere
The lowest, which is the layer that provides most of our weather & contains aproxamately four-fifths of the Earth's air, it extends only to a height of +/- 11 miles (17 kilometers) at the Equator and somewhat less at the Poles.
The name derives from a Greek word that refers to mixing, this is exactly what happens within the troposphere. As warm air rises it forms clouds and produces rain fall and in turn creates winds to stir the lands below. Typically, the higher you go into the troposphere, the colder it gets.

The Stratoshpere
Above the troposphere is the stratosphere which extends to a height of +/- 30 miles (50 kilometers) and includes the ozone layer, which blocks out most of the sun's harmful ultraviolet rays.
This layer is warmer than the troposphere because of the energy from the ultraviolet light absorbed by the ozone. At its base of the stratosphere it is extremely cold, aproxamately -110 degrees Fahrenheit (-80 degrees Celsius) and towards its top, the temperature would have risen back to a stage of freezing point.

The Mesoshpere
In this layer the air temperature drops again, down to nearly -180 degrees Fahrenheit (-120 degrees Celsius) at the top. Meteors generally burn up in at this point and would disintergrate like a drop of water on a piping hot stove element. It extends to a height of +/- 52 miles (85 kilometers). This is why the Earth's surface isn't pocked with meteor craters, like the moon's.

The Ionoshpere
Is where we would be entering Outer Space, it extends to about 430 miles (690 kilometers) and is so thin it's generally considered part of outer space. The International Space Station and many satellites orbit within this section of the atmoshpere and quite venerable to meteors but are avoided due to constant monitoring.

The ionosphere is named for the ions created within this layer by energetic particles from sunlight and outer space. The ions create an electrical layer that reflects radio waves, allowing radio messages to be sent across oceans in the days before communication satellites. Electrical displays in the ionosphere also create the auroras called the Northern and Southern Lights.

The Exoshpere
Beyond the ionosphere lies the exosphere, tenuous portion of the Earth's atmosphere which extends outward until it interacts with the solar wind. The Solar storms / winds compress the exosphere, when the sun is tranquil, this layer extends further outward like a balloon being released then inflated, constantly. Its top ranges from 620 miles (1,000 kilometers) to 6,214 miles (10,000 kilometers) above the surface and merges with interplanetary space.

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The Kruger Park..a place that is close at heart


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