1. The Sun and the Motions of Objects in the Solar System
Expectations: D3.4, D3.5
Objectives:
Describe the make up and structure of the Sun and explain how its energy warms Earth and supports life on the planet.
Explain the effects the Sun has on Earth
Explain the cause of Aurora Borealis

2. The Sun Our Star was born approx. 6 billion years ago
Emits energy (radiation) some of which is absorbed by the Earth’s atmosphere and some is reflected into space
This radiation is the driving force behind our weather and climate. It also provides energy for life to exist.

3. Structure Inner core First layer –radiative zone
Second layer- convective zone
Third layer- photosphere (5500ºC)
Sun’s atmosphere includes the chromosphere (65 500ºC) and corona (halo that extends millions of km)

4. Structure of the Sun

5. The Core Inside the core of the sun is where nuclear fusion occurs
Two atoms of hydrogen fuse together form one atom of helium and releases great amounts of energy
It is the hottest part of the Sun ( ºC)

6. How much energy?
During fusion, each gram of hydrogen releases million kJ of energy
That’s as much energy as you would get if you ate 1 trillion pizza slices!
And that’s only for 1 gram of hydrogen – the Sun has 2.0 x 1023 g of hydrogen!
Scientists predict it will last another 5 billion years

7. What is this energy used for?
Plants use sunlight to grow and produce food
Animals eat plants that are grown in sunlight
Coal was formed from the remains of prehistoric plants, so it is a form of stored energy from the Sun
Oil and gasoline are formed from the remains of prehistoric organisms, which obtained energy from the plants, and hence, the Sun

8. The Sun’s Surface Sunspots
A sunspot is a dark spot on the Sun’s surface that is cooler than the area surrounding it
The sunspot groups in this picture are as big as the giant planet Jupiter!

9. Sunspots The picture on the right is a close-up of some other sunspots
The larger sunspot on the right (top) is bigger than Earth!

10. Solar Flares
Gases and charged particles that are blasted above the surface of the Sun
Release huge amounts of energy

11. Effects on Earth Auroras
Shifting colours in the sky happen when charged particles from the Sun come in contact with Earth’s magnetic field
Northern lights (aurora borealis)

12. How Auroras Form

13. Aurora Borealis
This picture was taken in the North West Territories, Canada

14. Aurora Borealis

15. Northern Lights

16. Aurora Australis
This picture was taken in New Zealand

17. Aurora Colours
The type of gases in the atmosphere, density of the atmosphere, and the altitude of the aurora determine the possible colours
When particles strike oxygen, green or reddish-brown is produced
When particles strike nitrogen, red or blue is produced
Green is the most common of all auroras

18. Other Effects Communication disruptions and radiation hazards
Particles ejected by the Sun can damage information on satellites, therefore tv and cell phone disruption
Radiation in solar storms can be harmful to astronauts and people travelling in planes

19. Your Task
Complete here comes the Sun Storm worksheet.
Due for marks.

20. Homework
Page 312 # 2, 5, 7