1. Exploring the Universe
Chapter 26

2. 26.1 Energy From the Sun

3. Since you read the chapter
                                            
Since you read the chapter
We won’t be spending time on these vocab words that were part of your reading guide.

4. Review of Vocabulary
Core - central region, where nuclear fusion occurs.

5. How does the sun produce energy?
Energy is produced in its central region by the fusion of hydrogen nuclei into helium nuclei.
What new isotope is produced by this fusion reaction? Helium

6. Question: What new isotope is produced by this fusion reaction?
hydrogen-1
helium-4
oxygen-16
none

7. What new isotope is produced by this fusion reaction?
hydrogen-1
helium-4
oxygen-16
none

8. May the force be with you!
26.1 Forces in Balance
May the force be with you!

9. Why does the sun remain stable over time?
Inward pull of gravity balances the outward push of thermal pressure from nuclear fusion.
Sun will remain stable for another 5 billion years.

10. Question: What would happen to the sun if it began to run out of fuel?
It would become cooler very quickly.
The force of gravity would decrease.
Its core would expand as thermal pressure increased.
Its core would shrink as thermal pressure decreased.

11. What would happen to the sun if it began to run out of fuel?
It would become cooler very quickly.
The force of gravity would decrease.
Its core would expand as thermal pressure increased.
Its core would shrink as thermal pressure decreased.

12. Sunny’s pretty on the inside?
26.1 The Sun’s Interior
Sunny’s pretty on the inside?

13. Interior facts The sun’s interior consists of 3 parts.
Core
Radiation zone
Convection zone
Energy moves through the sun in two main ways:
Radiation
Convection

14. Review of Vocabulary
Radiation zone - region of highly compressed gas where energy is transferred by the radiation.

15. Review of Vocabulary
Convection zone - the outer layer of the sun's interior, where energy is transferred mainly by convection currents.

16. Remember how convection currents move…..

17. 26.1 The Sun’s Atmosphere
Very unlike Earths!

18. Exterior facts The sun's atmosphere consists of three layers.
Photosphere
Chromosphere
Corona
These regions are outside the convection zone.

19. Photosphere Innermost layer Visible surface of the sun
500 kilometers thick
Temp: approximately 5800 K

20. Chromosphere Middle layer Temp: increases to nearly 10,000 K
At high temperatures, hydrogen gas emits a reddish light.
This light gives it its name, which means “sphere of color.”
Can see this during a total solar eclipse.

21. Corona Outermost layer Gases in the corona are thin
Temp: Gases super hot (about 1 million K)
Thermal energy in it is relatively small.
Usually seen only during solar eclipses.

23. 26.1 Features of the Sun’s Atmosphere
You will use your notes and text to compare and contrast these features after lecture with table partner.

24. Sunny’s got a magnetic personality!
The sun's magnetic field produces striking features on and above its surface
Such as:
Sunspots
Prominences
Solar flares.

25. Sunspots
Areas of gas in the photosphere that are cooler than the surrounding gases.
Spots can be larger than Earth
Associated with intense magnetic fields on the sun.
Last from a few hours to a few months.
Numbers varies in cycles, with about 11 years separating one sunspot peak from the next.
During peak periods, there may be a hundred sunspots on the sun.

27. Prominences Huge loops of gas that erupt from sunspot regions.
Extend from the photo S into the chromo S and sometimes into the corona.
Travel along the magnetic field lines that connect sunspots.
Heights can be more than 100,000 kilometers above the sun's surface.

30. Solar Flares Sudden release of energy
Surface erupts dramatically, producing X-rays and hurling charged particles into space.
Heat the corona to a temps near 20 million K and produce solar wind.
High-energy particles and radiation can reach Earth
Cause magnetic storms in Earth's upper atmosphere.
Storms disrupt electric power transmission, radio, TV, and phone signals.
Like prominences, solar flares usually occur near sunspots.

33. Question: How can sunspots be recognized on the sun's surface?
Sunspots appear darker than the surrounding photosphere.
Sunspots appear lighter than the surrounding photosphere.
It is hard to distinguish sunspots from the surrounding photosphere.
Sunspots always appear in definite groups.

34. How can sunspots be recognized on the sun's surface?
Sunspots appear darker than the surrounding photosphere.
Sunspots appear lighter than the surrounding photosphere.
It is hard to distinguish sunspots from the surrounding photosphere.
Sunspots always appear in definite groups.

35. Let’s play…….

36. Name that feature!!

53. Joules of ultraviolet radiation
Great Job!
You win
200,000,000,000,000,000
Joules of ultraviolet radiation
View clip for review
Inside the Sun (6:16)