EARTH’S ATMOSPHERE

WHY IS IT IMPORTANT?

• Generate a classroom discussion

Called ‘Thin Blue Line’

Picture from International Space Station

Our fragile biosphere's only protection from the solar wind's full onslaught is provided by the Earth's atmosphere (the thin blue layer in the photograph) and its magnetic field (which acts as a shield against the sun's radiation and magnetic fields).

MIR SPACECRAFT

http://www.space.com/php/multimedia/imagegallery/

igviewer.php?imgid=743&gid=59

Mir's solar-array panel was damaged during a collision with an unmanned Progress re-supply ship on June 25, 1997 I

This is considered the worst accident in the space station's history

ACTIVITIES

• Layered Booklet

• Where does Space Begin?

WHERE IS IT?

                                                                              

How are the Layers Defined?

• Layers of the Atmosphere Activity

What is the atmosphere?

• Envelope of gasses that surrounds the Earth and protects us by blocking out dangerous rays from the sun

• Mixture of gasses that become thinner until it gradually reaches space

• Composed of nitrogen 97(%), oxygen (21%) and other gasses (1%)

WHAT IS IT MADE OF?

TROPOSPHERE

• All weather takes place within this layer

• It is a region of rising and falling packets of air; masses of air are very well mixed together.

• Air pressure at the top is 10% of that at sea level

• Temperature decreases with altitude

• Boundary with the next layer is called the tropopause

STRATOSPHERE

• Air flow in this layer is almost horizontal– Jet stream between 10-15 km– Influences weather patterns in troposphere

• Ozone exists in this layer– Responsible for absorbing the ultraviolet

radiation from the sun– Causes this layer to heat up

• Boundary is called the stratopause

MESOSPHERE

• Coldest layer– But this is where meteors burn up– http://video/google.com/videoplay?

docid=367189568812571611&q=australia+meteor

• Boundary called the mesopause

THERMOSPHERE

• DIVIDED INTO TWO SECTIONS

• UPPER LIMITS EXTENDS INTO THE VACUUM OF SPACE

IONOSPHERE

• Area ionized by solar radiation

• Different regions of the ionosphere make long distance radio communication possible by reflecting the radio waves back to earth

• Home to auroras

EXOSPHERE

• Region where atoms and molecules escape into space

Earth’s Magnetosphere

• The Earth generates a giant magnetic dipole field shaped like a bar magnet.

• It emerges from the middle of the Earth, with lines looping roughly north-south.

• The Earth's magnetic field tries to be the same shape as a bar magnet. – However, it gets bent out of shape by winds from the

Sun

• Earth's magnetic field changes over time, so the magnetic poles vary in strength and direction

Changing Colors of the Sky

• The color of the sky is determined by how much the atmosphere scatters sunlight– If one could add more molecules to our

atmosphere, its color would be yellow

• Near sunrise or sunset, the rays of sunlight strike the atmosphere at a low angle– Shorter wavelengths (blues) are scattered– Longer wavelengths (reds, oranges, yellows)

make it through