1. THE SUN: Solar Energy

2. The Sun as a Star
It’s light is the major source of energy for all planets and life on Earth.
It’s an “average” star
4.5 billion years old – ½ way through life cycle

4. Sun Layers 1. Core = 14,500,000 K 2. Radiative Zone = 2,100,000 K
3. Convection Zone = 1,000,000 K
4. Photosphere = 6,000K
5. Chromosphere = 27,000 K
6. Corona = ,000,000 K
7. Sunspots = 5,000 K
8. Granules
9. Solar Flare

5. Sun: A Nuclear Reactor The Sun does not “burn” like wood.
The Sun is made of:
78% Hydrogen
20% Helium
2% heavier elements
Because it’s so large, the gravity is very strong. So, deep inside the temperature and pressure are very high.

6. Sun: A Nuclear Reactor (con’t)
Nuclear Fusion: the process where 2 Hydrogen atoms fuse together to make 1 Helium atom (H + H = He) …it’s not that simple, however.
This is a nuclear reaction and it releases energy in the form of heat and light.

8. Ways Heat Energy can be Transferred
Conduction: Heat energy transferred by contact. Energy from a higher energy atom or molecule gets passed on to one with less energy when they bump into each other.

9. Ways Heat Energy can be Transferred (con’t)
2. Convection: heat energy transferred by movement of a liquid or gas. As warm air gains heat energy, it becomes less dense and rises. Cooler air sinks.

10. Ways Heat Energy can be Transferred (con’t)
3. Radiation: Heat energy transferred through space.
It’s how Solar energy travels to Earth.

11. Ways Heat Energy can be Transferred – all in one!
Draw a simplified diagram of this and label the types of heat transfer.

12. Solar Energy Energy comes in many forms, such as heat and light.
Solar energy (energy from the Sun) travels through space as an electromagnetic wave.

13. Electromagnetic Radiation
The Sun gives off these types of light in varying amounts. Radio waves have the longest wavelength & least energy, Gamma Rays have the shortest wavelength & the most energy. All of these travel at 300,000 km/sec in space.

14. Electromagnetic Radiation

15. Solar Energy = Electromagnetic Radiation
The 2 main types of solar radiation (aka Electromagnet radiation) are heat (aka infrared rays) and light (aka visible light).
The Sun also gives off some UV light (7%) and a tiny amount of radio waves, microwaves, X-rays, Gamma rays.