1. The Sun and Our Earth The Structure of Our Sun The Energy of Our Sun
The Activity of Our Sun
The Affects of Our Sun on Earth

2. The Structure of the Sun

4. The Sun’s Interior The core at the center of the sun ionized gas
extremely dense (10x denser than iron)
electrons are stripped away from nuclei
nuclear fusion occurs here

5. The Radiative Zone zone surrounding the core
energy moves outward through this zone from the core in electromagnetic waves

6. Convective Zone surrounds the radiative zone
energy produced in the core moves through this zone by convection
hot gases carry energy to the sun’s surface.

7. The Sun’s Exterior or the Atmosphere of the Sun
The Photosphere
Made up of gases from the Convection Zone
The energy given off is in the form of visible light
The Chromosphere
Glows with reddish light
gases form narrow jets of hot gas that shoot outward and then fade away
The Corona
Huge region of gas = crown
Not very dense
Has a strong magnetic field

8. The Energy of Our Sun Composition: Gases that make up the sun are:
Hydrogen – 90%
Helium – 8%
Gases create energy through nuclear fusion.
Nuclear fusion: the process of combining the nuclei of small atoms to form more massive nuclei. A small amount of matter is destroyed or converted into energy.

9. Nuclear Fusion

10. Nuclear Fusion:
Step 1: Two protons from hydrogen nuclei collide and fuse. The positive charge of one of the protons is neutralized as that proton emits a particle. That proton then becomes a neutron and now there is a proton-neutron pair.
Step 2: Another proton combines with this proton-neutron pair to produce a nucleus made up of two protons and one neutron.
Step 3: Two nuclei made up of two protons and one neutron collide and fuse. Two protons are released. The two protons and two neutrons fuse together to form a helium nucleus.

11. The Sun’s Magnetic Field
Movement of the Convection Zone and the rotation of the sun produces magnetic fields on the sun.

12. Sunspots Solar Ejections
Activity of the Sun
Sunspots
Solar Ejections

13. Sunspots

14. Sun spots
The Cause:
Magnetic fields causes the convection to slow in the convection zone. Slower convection causes a decrease in the amount of gas that is transferring energy from the core to the photosphere.
Because less energy is transferred, some regions of the photosphere are cooler than the surrounding region

15. Sunspots Appearance These areas appear darker
These areas will appear more grainier
These areas are cooler
These areas will have a stronger magnetic field

16. Sunspots The Sunspot Cycle
Number and position of sunspots varies every 11 years.
The cycle begins when the number is low and starts an increase in the amount.
The cycle ends when the number reaches a minimum again.
Sunspots appear in groups midway between the sun’s poles and the sun’s equator
Sunspots tell us the sun rotates

17. Sunspot
The Graph of Sunspots

18. Solar Wind
Electrons and electrically charged particles called ions escape the solar magnetic field and move into space

19. Solar Ejections What are they?
Atomic particles are emitted by the sun during solar events
What solar events?
Prominences
Solar Flares
Coronal Mass Ejections

20. Solar Ejections Prominences:
Great clouds of sun’s gases from the photosphere
They are caused by disturbances in the magnetic field
They form Huge arches high above the sun’s surface

21. Solar Ejections Solar Flares:
A sudden eruption of electrically charged particles
It is a release of energy stored in the magnetic field of the sunspots
There can be formation of coronal loops
Some particles can escape into space.

22. Solar Ejections Coronal Mass Ejections:
Electrically charged particles of the sun can escape into space.
These particles are parts of the corona.
CME’s strike the Earth’s magnetosphere
(Earth’s magnetic field)
CME’s can cause a disturbance in the
Earth’s magnetic field called
geomagnetic storms

23. The Sun Affects Our Earth
Geomagnetic Storms
Auroras
Sunspots and Climate

24. Geomagnetic Storms Caused by coronal mass ejections – CME’s
Sun’s particles strike the Earth’s magnetic field generating geomagnetic storms
Geomagnetic storms can interfere with radio communications, damage satellites, can lead to blackouts
Small storms occur each month and severe storms occur less than once per year

25. Auroras
Electrically charged particles from the sun cluster at the Earth’s poles.
These particles excite the atoms and gas molecules in the upper atmosphere causing them to glow
Known as the aurora borealis or northern lights.

26. Climate Changes from Sunspots
Affect on Earth
The fewer the sunspots, the cooler the sun and the cooler the climate
The more the sunspots, the hotter the sun and the warmer the climate
Sunspots have a direct effect on the Earth’s climate