The SunThe Sun

Energy from the SunEnergy from the Sun

Where do people get the Where do people get the energy they need to live?energy they need to live?

• From food they eat, including From food they eat, including plants and other animals.plants and other animals.

Where do plants get their Where do plants get their energy?energy?

• They convert energy from the sun’s They convert energy from the sun’s light into food energy.light into food energy.

How do plants serve as a link How do plants serve as a link between the sun’s energy and between the sun’s energy and people?people?• When an animal eats plants—or eats When an animal eats plants—or eats

animals that have eaten plants—it gets animals that have eaten plants—it gets food energy that started with the sun.food energy that started with the sun.

Look at pictures B116-117Look at pictures B116-117

• How do the waves that travel from How do the waves that travel from the sun to the Earth differ?the sun to the Earth differ?

Some are large, stretched-out waves; others are small, closely packed waves. Each carries a different amount of energy.

The sun produces energy by The sun produces energy by joining particles in a process joining particles in a process called fusion.called fusion.

• Which particles are fused in the sun Which particles are fused in the sun to produce energy?to produce energy?

What do the fused particles form?

How does this process produce energy?

What is needed for fusion to occur?

FusionFusion

NO! Not this kind of fusion!!!

fusionfusion

The sun consists of layers of The sun consists of layers of hot gases.hot gases.

• What gases make up the sun?What gases make up the sun?

Is each layer really distinct? Explain your answer.

Look at the pictures of the Look at the pictures of the sun’s structure on pages B118-sun’s structure on pages B118-B119B119• What are the layers of the sun, from What are the layers of the sun, from

the innermost to the outermost?the innermost to the outermost?Why does the surface of the sun appear grainy?

What layer of the sun do solar flares come from?

Where do sunspots occur? Why do they appear dark?

Where is the sun’s core Where is the sun’s core located?located?

• At its center.At its center.

What can you infer about the What can you infer about the pressure in the core?pressure in the core?

• It is tremendous, greater than It is tremendous, greater than anywhere else on the sun.anywhere else on the sun.

If this tremendous pressure is If this tremendous pressure is causing fusion of hydrogen causing fusion of hydrogen nuclei in the core, what can nuclei in the core, what can you infer about the you infer about the temperature of the core?temperature of the core?

• It must be very high.It must be very high.