1. THE SUN NOTES

2. The Layers and Features of the Sun

3. LAYERS of the Interior THE CORE- Nuclear Fusion occurs
Diameter- 400,000 km
The Radiation Zone- region of compressed gas and energy is transferred by electromagnetic waves.
Thickness- 300,000 km
Very Dense zone- can take energy 100,000 years to pass through
The Convection Zone- energy is transferred outward through convection currents
Thickness- 200,000 km

4. The Layers and Features of the Sun

5. Layers of the Atmosphere
Photosphere- Visible surface of the sun (photo=light) that is not solid but considered the surface
500 km thick and 5800 degrees Kelvin
Chromosphere- Middle layer of the atmosphere that emits a reddish light (chromosphere means sphere of color)
10,000 degrees Kelvin
Visible only during a total solar eclipse
Corona- outermost layer means the crown
1million degrees Kelvin
Low density- extends millions of miles into space
Where solar winds come from and produces the auroras when they enter the earth’s atmosphere.

6. The Layers and Features of the Sun

7. Features on the Sun
Sun Spots- areas of gas that are cooler than the surrounding gas
Can be larger than the size of Earth and can last hours to a few months
Prominences- huge loops of gas that erupt from the sun spot regions
Can reach heights of more than 100,000 km above the sun’s surface
Solar Flares- Sun’s surface erupts producing X-rays and charged particles
Occur near sunspots
Heat the corona up to 20 million Kelvin
When the particles reach Earth they can cause magnetic storms which disrupt power, radio, TV, cell phone reception

8. The Layers and Features of the Sun

9. The Sun’s Energy
Most Energy is in the form of electromagnetic radiation
The sun is approx. 4.6 Billion years old
Energy is produced in its core by the fusion of hydrogen
Hydrogen nuclei collide to form helium
This releases large amount of energy
Forces in the Sun- inward and outward forces must be equal
Thermal Pressure pushing out = Gravity pulling in
The sun remains stable as long as there is a steady energy source = estimated time… 5 billion years

10. Incoming Solar Radiation on Earth
Of 100% of the incoming solar radiation about 51% is absorbed by the earth and the rest either is
19 %Absorbed by the atmosphere
30% Reflected or scattered back into space by earth or clouds

11. Scattering Why is the sky blue? Why are our sunsets red?
Molecules of dust and gas will interfere with the incoming solar radiation. It will scatter the shorter wavelengths of visible light which happen to be the color blue.
When the sun is in a lower angle in the sky like during sunrise and sunset, the rays have to travel longer and through a thicker atmosphere. The blue is scattered to a large extent and we see what is left in the spectrum which is the orange/red colors.