93 million miles from Earth
150 million kilometers from Earth
99.8% of the mass of our solar system

The Sun’s Energy
• The core of the sun acts like a furnace.
• The sun’s energy comes from nuclear fusion.
• Nuclear fusion- hydrogen atoms join together to form helium atoms at extremely high temperatures.
• Sun’s core- 15 million degrees Celsius
• The total mass of the helium atoms produces is slightly less than the total mass of the hydrogen atoms. The difference is the amount of heat and light energy given off by the sun.
• Hydrogen and helium are the most abundant elements in the universe. Why? They are the gases stars are made of!

The Sun’s Atmosphere
• 3 layers:
• 1) photosphere- inner layer of the sun’s atmosphere; the part of the sun we see when we look at the sun
• 2) chromosphere-reddish glow just around the photosphere seen during a solar eclipse; middle layer
• 3) corona- means “crown;” outer layer that looks like a halo; seen during a complete solar eclipse; gives off solar wind- a stream of electrically charged particles( cause the aurora borealis at the North and South Poles.

Events on the Sun
• sunspots- small, dark areas on the sun’s surface; cooler gases on the sun
• prominences-reddish loops of gas that project from the surface of the sun like fingers
• solar flares-explosions of hydrogen gas that occur as sunspot regions connect and release large amounts of energy

corona

sunspots

prominences

Solar flares

solar wind

animation of solar flares
• http://www.pond5.com/stockfootage/80035/solar-flares-17-2997.html

animation of prominences
• http://science.nasa.gov/headlines/images/pro minence/prominence_10jan00.mov

Classwork Quiz
• Match the following pictures to the solar event they represent:
• 1. explosions on the 2. fingerlike sun’s surface projections

3. This picture shows electrically charged particles leaving the suns’ corona.

4. What are these dark areas called?

5. Which part of the sun acts as it’s furnace?
6. Where does the sun’s energy come from?
7. What are the 2 most abundant elements in the universe?

8. Which layer of the sun is what we see from Earth?
9. Which layer of the sun’s atmosphere is called it’s crown or halo?
10. Which layer of the sun’s atmosphere provides a reddish color during a solar eclipse?