1. Bell Ringer
The outer layer of the Sun’s atmosphere is actually hotter than the interior of the Sun. Explain why you believe this is so.

2. THE SUN (SOL) (Page 45)

3. Essential Question:
*What are the unique properties of the sun?

4. *The Sun (A star) - A giant ball of glowing gases
-- 74% hydrogen, 25% helium, 1% other gases

5. *The sun’s structure consists of two parts – interior and atmosphere.

6. Part 1 -Structure of the Sun
(Interior)

7. Core – center layer *energy is produced here through a process called fusion

8. Temperature reaches 27,000⁰ F (15,000⁰ C)
*Fusion – intense pressure, friction, and heat causes the hydrogen atoms to combine (fuse) together, converting them to helium atoms (2 H → 1 He)
Temperature reaches 27,000⁰ F (15,000⁰ C)

9. Radiative Zone
where the energy radiates away from the core toward the Sun’s surface

10. Convective Zone
where the energy is moved to the Sun’s surface by convection currents

11. Structure of the Sun
(Atmosphere)

12. Structure of the Sun (Atmosphere)
Photosphere - the visible surface of the sun
*approximately 300 miles thick
*temperature about 10,000⁰ F (5,500⁰ C)
*the light we see takes 8 minutes to reach the Earth

13. Chromosphere - middle layer of sun’s atmosphere

14. Chromosphere *about 1,200 miles thick
*visible only during a total solar eclipse as a reddish glow

15. Corona - outer layer of sun’s atmosphere

16. Corona *The temperature here reaches over 3,500,000⁰ F
*emits (sends out) the electro-magnetic radiation
*Visible only during a total solar eclipse as white plumes

17. Corona
Chromosphere
Photosphere
Convective Zone
Radiative Zone
Core

18. Bell Ringer
If the Sun is so hot that we can’t directly observe it, how are scientists able to determine how hot it is?

19. THE SUN (Page 46)

20. Part 2 – Solar Activity

21. Essential Questions:
*How does the sun rotate differently than the planets?
*How do events on the sun affect events on the Earth?

22. *Differential Rotation – different parts of the Sun rotate at different speeds (faster at the equator, slower toward the poles)
*the sun is a ball of gases, not solid like the Earth

23. Prominence – giant bursts of gases looping out from the sun
*can last from several hours to a day
*many Earths could fit inside one

24. Solar Flare - an explosive burst of energy from the sun
*appears as very bright spots on the photosphere
*Similar to a volcanic eruption on Earth

25. Sunspots - dark areas on the sun’s surface
*cooler regions of the photosphere caused by a change in the sun’s magnetic field

26. Solar wind - a steady stream of charged particles emitted from the sun
EARTH
*travels about 1,000,000 mph throughout the SS

27. *The Earth is protected by its magnetic field

28. *How does solar activity affect conditions on Earth?
*Higher than normal bursts of radiation can affect the health of humans

29. *How does solar activity affect conditions on Earth?
*Extreme solar flares and the solar wind can affect satellites, astronauts, GPS systems, jet airplanes, and electrical systems and devices.

30. *How do we know what we know about the Sun?

31. Conclusion
Using a Venn Diagram,
Compare and Contrast
The Sun and The Earth