1. The Sun *Our closest star
*Accounts for 99.8% of the solar system’s total mass
*because of this, it exerts powerful gravitational force throughout the solar system
*this force decreases with distance but is strong enough to hold all planets in orbit

2. Sun’s Interior Ball of glowing gas, (not a solid surface like Earth)
¾ Hydrogen
¼ Helium
Small amounts of other elements
Has an interior
Has an atmosphere

3. Sun’s Interior Has 3 Zones:
Core
Radiation zone
Convection zone
This Photo by Unknown Author is licensed under CC BY-SA

4. Core Central region of sun Energy comes from nuclear fusion
Hydrogen atoms join together to form helium in this process
Occurs under conditions of high temperature and pressure (about 15 million degrees Celsius
Energy slowly moves out from the core, eventually escaping into space

5. Radiation Zone Middle layer of sun’s interior Tightly packed gas
Energy is transferred in form of electromagnetic radiation
Very dense
*because of its density, it takes 100,000 years for energy to move through it

6. Convection Zone Outermost layer of sun’s interior
Hot gases rise from bottom of this zone
Gases cool as they get to the top of this zone
Loops of gas form and move toward the sun’s surface

7. Sun’s Atmosphere
Photosphere
Chromosphere
Corona

8. Photosphere Inner layer of atmosphere
Seen when you look at an image of the sun
Considered to be sun’s surface layer
Moon blocks the light of photosphere during solar eclipse

9. Chromosphere Means “color sphere”
This Photo by Unknown Author is licensed under CC BY-SA
Chromosphere
Means “color sphere”
Reddish glow that appears during a solar eclipse is cause by this layer

10. Corona “white halo” during a solar eclipse Means “crown” in Latin
This Photo by Unknown Author is licensed under CC BY-SA-NC
“white halo” during a solar eclipse
Means “crown” in Latin
Corona extends into space for millions of kilometers
Thins into streams of electrically charged particles called solar wind

11. Layers of the Sun
This Photo by Unknown Author is licensed under CC BY-SA-NC

12. Sun’s Features
Sunspots
Prominences
Solar flares

13. Sunspots Dark spots on sun’s surface
Sunspots are larger than Earth (but appear small)
Cooler than the gases around them, so it is darker and doesn’t give off as much light
Appears to move across sun’s surface
Proves sun rotates on its axis just like Earth does
This Photo by Unknown Author is licensed under CC BY-SA

14. Huge, reddish loops of gas
Prominences
Huge, reddish loops of gas
Loops can be seen extending over the edge of the sun
This Photo by Unknown Author is licensed under CC BY-SA-NC

15. Solar Flares Magnetic energy Gas eruptions into space
This Photo by Unknown Author is licensed under CC BY-NC-ND