1. The Sun Average in size… yes AVERAGE!!
Mass is almost times that of Earth and a volume that is times the volume of Earth!
Appears to be so much bigger and brighter than other stars because it is so close to Earth

2. The earth is 150 000 000 (1.5 x 108) km from the sun
1 Astronomical Unit (A.U.) = distance from sun to earth
The next nearest star to the Sun is Proxima Centauri at 40 trillion (4.01 x 1013) km from Earth.
Most stars are more than 100 trillion (1.0 x 1014) km from Earth.

3. The Structure of the Sun

4. The Sun’s Surface
Sunspots
dark surface spots that are cooler than surrounding area
Solar Flares
gases and charged particles expelled above the active sunspot
Solar Prominences
low-energy gas eruptions from the Sun’s surface that extends thousands of kilometres into space

5. Layers of the Sun’s Atmosphere
Above the surface of the sun is its atmosphere, which consists of three parts:
Corona
5800 oC
gleaming white, halo-like – extends millions of kms into space
Chromosphere oC
Photosphere
5 500 oC
The layer just below the Chromosphere where the light we see originates.

6. The Inside of the Sun Convective zone
The outermost ring of the sun, comprising the 30 percent of its radius.
Radiative zone
The section immediately surrounding the core, comprising 45 percent of its radius.
Core
hottest part of the Sun - reaching oC
Energy released by nuclear fusion continues to move outward until it reaches the photosphere

7. process called nuclear fusion occurring in its core
Composition 75% hydrogen 25% helium (with small amounts of other gases)
Energy Source
process called nuclear fusion occurring in its core
the temperature and pressure are so high H fuses to become He and releases tremendous amounts of energy
Life expectancy 5 billion years old

8. The Sun’s Effects on Earth
The Aurora Borealis (Northern Lights)
The Northern Lights are the result of collisions between gaseous particles in the Earth's atmosphere with charged particles released from the sun's atmosphere.

9. Solar winds travelling toward Earth follow the lines of magnetic force created by Earth’s magnetic field (which is strongest near the NORTH and SOUTH poles).
Near the poles, they come in contact with particles in Earth’s atmosphere, producing a display of light in the night sky.

10. Northern Lights = Aurora Borealis Southern Lights = Aurora Australis

11. Class/Homework
Pg. 312 #1, 2, 6, 8, 9