1. Chapter 26 THE SUN

2. Sun Facts • Size 860,000 miles in diameter • Earth is only 7921 miles

3. 1 million Earths would fit inside the sun

4. Composition of the Sun • 90% hydrogen • 10%_________

5. 5,000,000,000 years old (5 billion) • Distance 91.5 to 94.5 million miles from Earth • Rotates every 26 days • An average- sun is gaseous and not all of it spins at the same speed • Equator spins faster than the poles

7. Kitt Peak Solar Observatory-Arizona

8. Houses The McMath–Pierce solar telescope is a reflecting solar telescope • Contains a third mirror that take the image to an observation room-so you don’t look directly at the Sun

9. How to safely observe the Sun

10. Video: solar max • https://www.youtube.com/watch?v=VQ_HrtwIfRo

11. Sun Handout • Surface features and structure

12. 1. Photosphere- surface of the sun, we see it as bright yellow. Made of millions of individual cells called granulas (10,000 degrees F)

13. Atmosphere • 2. chromosphere- lower part near the surface • 3. corona upper atmosphere- can be seen by an eclipse, mainly escaping gasses

14. 4. convection zone- cool gasses fall, heats up and the now warmer gasses rise • 5. radiative zone- takes 1 million years for one photon to travel thru this zone

15. 6. sunspots- areas that are cooler than the rest of the photosphere (only 6300 degrees Fahrenheit) -they come and go in an 11 year cycle -they help demonstrate the rotation of the sun

16. 7. prominance- arch of gas coming from a sunspot • 8. solar wind- charged particles that fly off into space • Magnetic storms- solar winds that interact with our magnetic field- may cause disruption in telephone and radio • Auroras- solar wind interacting with magnetic field at our poles, creating colors

17. 9. Core- where energy is produced thru fusion • 4 hydrogen fused to make 1 helium

18. Copernicus • Challenged the idea of Geocentric (everything revolves around the earth) • - 1543 published theory that the sun is at the center and planets revolve around it. This idea is called “Heliocentric”

19. Bruno- Astronomer who burned at the stake for Copernicus

21. Keplers lawsThree Laws of Planetary Motion • Johannes Kepler- German Astronomer published in 1609 “The Laws Of Planetary Motion”

22. Tycho Brahe

23. Law # 1 • The orbit of a planet is an ellipse with the sun at one focus • The distance from a planet to the Sun is always changing

26. LAW #2 • A line from a planet to the sun sweeps an area of equal area in equal time • The speed of the planet is always changing • Earth’s average speed is 66,000 mph • (right now we are slowing down)

29. LAW #3 • The further a planet is from the sun, the longer its period of revolution • Period= 1 revolution around the sun in years

30. Orbit Period- time it takes a planet to orbit the sun once • Mercury 0.24 yr • Venus 0.61yr • Earth 1yr • Mars 1.88 yr • Jupiter 11.86 yr • Saturn 29.46 yr • Uranus 84.01 yr • Neptune 164.8 yr

32. How to remember the order of the planets