1. Warm-Up
Imagine that the Sun has completely burned out. How would this affect planet Earth? Write down as many possibilities as you can think of. Be sure to think about the land, the water, and all living things. Be specific!
You need to be busy on this by the time the bell rings!

2. The Sun and its Energy 2

3. Think About It…
Is it possible to make electricity by using the same process that powers the Sun?

4. Focus Question…
What process powers the Sun and what forms of Energy does that process produce?

5. A Little Bit About the Sun…
Our Sun is a star, and the largest object in the Solar System. (99% of the Solar Systems total mass)
The Sun is 330,000 times as massive as Earth!
Scientists cannot directly observe the inside of the Sun, but can explain much about it through the use of computer models.
A pair of dice with the density of the Sun…
would weigh 2 pounds!

6. A Little Bit More About the Sun…
The inside of the Sun is gaseous due to its high temperature. (1 x 10^7 K)
Because of the high temperature, many of the gases inside of the Sun are ionized. This means they are composed only of atomic nuclei and electrons. This state of matter is called PLASMA.
The outside of the Sun, however, is not hot enough to be plasma.

7. Parts of the Sun
The sun has a core, a radioactive zone, and a convective zone.
The sun is composed of hydrogen and helium, and has no solid surface.
Compared to other stars, our sun is medium sized and has a medium temperature. However, it is still VERY hot!

8. The Sun’s Atmosphere… Photosphere… the lowest layer 400 km thick
Hot! (9980 degrees Fahrenheit)
the visible part of the Sun because most of the light given off by the sun comes from this layer.

9. The Sun’s Atmosphere… Chromosphere… Above the photosphere
2500 km thick
Very hot! (53,540 degrees Fahrenheit)
Can only be seen during a solar eclipse or when using special viewing filters.

10. The Sun’s Atmosphere… Corona…
Extends several million km from the top of the chromosphere
Very low density Extremely hot! (Upwards of 2,699,540 degrees Fahrenheit)
Can only be seen during a solar eclipse or when using special instruments to block out the photosphere.

11. Ways of Producing Energy
Combustion
Fission
Fusion

12. Combustion
The burning of a fuel in the presence of oxygen to produce heat and light.
Burning wood or coal
Burning fossil fuels 12

13. Fission versus Fusion
Fission: The process in which heavy atomic nuclei split into smaller, lighter nuclei. This process is used in nuclear power plants to produce electricity. Fusion: The process in a star’s core in which lightweight hydrogen nuclei combine into heavier helium nuclei. This process produces the radiant energy of stars (including our Sun).

14. Fission 14

15. Fusion

16. During fusion…
The mass that is lost when two hydrogen nuclei combine to form helium is not destroyed but converted into energy.
Albert Einstein’s theory of special relativity explains this!
E=mc2
(E=energy) (m=mass) (c=speed of light)
To put it simply, matter cannot be created or destroyed, but it can be converted to energy, and energy can be converted to matter.

17. What if humans could control Fusion?
Government hopes fusion provides clean, limitless energy source …
CHINA HOPES FUSION REACTOR TEST A SUCCESS
“BEIJING - Scientists on Thursday carried out China's first successful test of an experimental fusion reactor, powered by the process that fuels the sun, a research institute spokeswoman said.
China, the United States and other governments are pursuing fusion research in hopes that it could become a clean, potentially limitless energy source.
Fusion produces little radioactive waste, unlike fission, which powers conventional nuclear reactors.”
updated 3:22 p.m. ET, Thurs., Sept. 28, 2006

18. Warm Up
On a new sheet of paper, explain the differences between nuclear fission and nuclear fusion. Include as many details as possible to demonstrate how these two processes differ from each other. Be sure to refer to your notes!
Do your best! I am taking this up!

19. The Sun’s Energy…
Electromagnetic Radiation consists of electric and magnetic disturbances that travel through space as waves.
This includes radio waves, microwaves, infrared energy, visible light, ultraviolet radiation, x-rays, and gamma rays.
All of these forms of EM energy are organized into the Electromagnetic Spectrum.
Electromagnetic energy is classified by wavelength and moves at the speed of light

20. The Electromagnetic Spectrum…
This is the dangerous side!

21. The Earth’s Protective Atmosphere
The Earth’s atmosphere protects us from harmful electromagnetic radiation.
The ozone layer blocks ultraviolet radiation which is harmful to all living things.
Water vapor and carbon dioxide reflect or absorb other types of harmful electromagnetic radiation.

22. Solar Wind and Earth’s Magnetic Field
Solar wind is…
A supersonic plasma of charged particles that flows outward from the corona at high speeds.
Solar wind bathes each planet in a flood of high-energy particles.
So, considering this, how do we survive on planet Earth?

23. Solar Wind and Earth’s Magnetic Field
Earth’s magnetic field protects us from the solar wind by deflecting the particles and trapping them in two huge rings called the Van Allen belts.

25. Solar Wind and Earth’s Magnetic Field
The auroras are created when high-energy particles in the Van Allen belts collide with gases in Earth’s atmosphere and give off light.

27. Energy For Earth…
The Sun’s energy reaches Earth by the process of radiation.
Radiation is the transfer of energy through space by electromagnetic waves.

28. What Happens to the Sun’s Energy?28

29. Differential Heating…
Water heats up and cools down slower than land does.
This is called differential heating.
This helps moderate the climate in coastal areas.

30. Differential Heating

31. Energy for Earth…
Conduction is the transfer of energy that occurs when molecules collide (touch).
The air molecules above Earth’s surface are warmed by the process of conduction. 31

32. Energy for Earth…
Convection is the transfer of energy by the flow of a heated substance.
Warm air rises.
When the warm air gets high enough, it cools and sinks.
This creates a convection current. 32

33. Energy for Photosynthesis…
During photosynthesis, solar energy is transformed into chemical energy.
This occurs in plants, algae and some bacteria.
For this to occur, there must be water, CO2, and sunlight.
In plants, this occurs in chloroplasts.

34. Radiation, Conduction, or Convection?

35. Food From the Sun!

36. Warm Up
By the time the bell rings, have your Nuclear Fission vs. Nuclear Fusion homework out and ready to turn in.
Also, have yesterday’s study guide, Stars, out and ready to review.

37. When you finish… Go to www.nasa.gov (www.nasa.gov)
Click “For Students” at the top of the page.
Then click on “For Students” in the left hand margin.
Then click on “Grades 5-8” in the left hand margin. (I know you all are older than that, but that is where the fun stuff is!)
Scroll down to the “Fun and Games” section in the middle of the page.
Click on “View Archives” in the “Fun and Games” section.
Once you are in the “Fun and Games” archive section, you may play any of the games and activities as long as they do not require you to download or install anything.