1. The Sun

2. Sun Considered a medium STAR 93,000,000 miles away from Earth 1.39 million kilometers in diameter (one million Earths can fit inside the sun State of matter - plasma

3. More on the Sun Contains 99% of mass of our solar system Made of 82% hydrogen, 17% helium, 1% other

4. Our Sun compared to other suns!

5. Our Sun compared to other even larger suns!

6. The sun’s structure Core – 27 million degrees Fahrenheit, where thermonuclear fusion occurs Photosphere – innermost part of sun’s atmosphere but still visible to us, made of hydrogen gas that burns at 9000 degrees Fahrenheit – causes it to glow yellow

7. The sun’s structure Chromosphere – inner atmosphere, region of glowing gas; red color caused by ionization of hydrogen Corona – outer atmosphere, thin layer of gas that extends millions of km beyond chromosphere

8. The sun’s corona

9. Thermonuclear fusion The sun is so bright because it goes through thermonuclear fusion – when hydrogen atoms get turned into helium atoms due to high heat and pressure –Releases massive amounts of heat and light as a byproduct –This energy and light released from the sun takes 8 minutes to reach us

10. What is a sunspot? An area on the sun that has extremely strong magnetic activity The magnetic activity does NOT allow convection so it is a cool region Looks like a dark spot Lasts 2 weeks and only occurs in 11 year cycles Magnetic fields

11. Sunspot activity since 1760

12. Recent sunspot activity

13. 2013 We are still in solar maximum. What is happening?

14. What else should we know about sunspots? They can cause solar flares –When hot gases erupt from the surface of the sun sending ions and radiation into space Solar flares create solar winds

15. Solar Flares

16. Close Up of Flares

17. Solar prominence Streamers of hot gases arching above photosphere Do not disrupt Earth’s communications

18. Solar winds Every 11 years, the suns magnetic poles reverse and release energy –Billions of tons of particles fire into space at 1 million mph, at the peak it is called the solar maximum, speeds can reach 3 million mph –We are in a solar maximum now

19. Solar Wind – a continuous flow of electrons and protons from the sun into space

20. How is Earth protected? Magnetosphere- magnetic field that is surrounding the Earth Without the magnetic field, the solar winds would be much more dangerous

21. Earth’s Magnetosphere

22. Solar Flares in the news

23. Why does this matter? Strong solar flares and sunspots can damage our communication systems and electrical systems Also increase aurora activity Aurora Borealis and Australis – lights caused by interactions of atomic particles between solar wind and the ionosphere

24. Effect of solar flares and solar winds http://www.teachersdomain.org/resource/e ss05.sci.ess.eiu.solarwind/http://www.teachersdomain.org/resource/e ss05.sci.ess.eiu.solarwind/ https://www.youtube.com/watch?v=Hueen 7jPi0whttps://www.youtube.com/watch?v=Hueen 7jPi0w

25. SDO (solar dynamics observatory) AIA images the outer layer of the Sun's atmosphere (corona) at temperatures from 20 thousand to 20 million degrees. EVE keeps track of the extreme ultraviolet (EUV) rays that the Sun sends towards us. UV rays cause skin cancer. Extreme UV rays are even more dangerous. Our atmosphere absorbs UV, keeping us safe. HMI will measure the ripples and the magnetic fields on the surface of the Sun (photosphere) to determine what is happening on the inside.

26. Photo taken in extreme ultraviolet on March 30, 2010 by the Solar Dynamics Observatory that was launched by NASA on February 11, 2010.

27. SDO photograph