Layers of the Sun- Lesson 3

The Sun is Our Local Star

The Sun is the only star in our solar system. Astronomers have been

able to study the Sun in more detail than other stars because it is much closer to Earth. As a result, they have learned a great deal about its size and composition and the way it produces energy.

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​The Sun produces energy from hydrogen.

Multiple Choice

The sun is a ____, while Earth is a ______.

• star; planet

• star; star

• planet; star

• planet; planet

The Sun is far larger than any of the planets. It contains 99.9 percent

of the mass of the entire solar system. For comparison, imagine that Earth had the mass of a sparrow; then the Sun would have the mass of an elephant.

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​The Sun produces energy from hydrogen.

Multiple Choice

The Sun is far smaller than any of the planets in thr Solar System

• True

• False

The Sun consists mostly of hydrogen gas. Energy is produced when hydrogen in the Sun’s interior turns into helium. This energy is the

source of light and warmth that make life possible on Earth.

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​The Sun produces energy from hydrogen.

Multiple Choice

The Sun is made up of what 2 elements?

• Helium and Boron

• Hydrogen and Oxygen

• Hydrogen and Helium

• Hydrogen and Argon

Although the Sun is made entirely of gas, it does have a structure.

Energy produced in the center of the Sun flows out through the Sun’s

layers in different forms, including visible light.

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​Energy flows through the Sun’s layers.

The center of the Sun, called the core, is made of very dense gas. Temperatures reach about 15 million degrees Celsius. Under these extreme conditions, some hydrogen particles collide and combine to form helium in a process called FUSION. The process releases energy that travels through the core by radiation.

Core

Energy from the core moves by radiation through a thick layer called the radiative zone. Although this layer is very hot and dense, conditions in the radiative zone are not extreme

enough for fusion to occur.

Radiative Zone

In the convection zone, energy moves mainly by convection. is the transfer of energy from place to place by the motion of heated gas or liquid. Rising currents of hot gas in the convection zone carry energy toward the Sun’s surface.

Convection Zone

​The Sun’s Interior: The Sun’s interior generally becomes cooler and less dense as you move away from the center.

Multiple Choice

Rising currents of hot gas in the convection zone carry energy _______ the Sun’s surface.

• toward

• away from

Multiple Choice

The is hottest in the convective zone.

• True

• False

Multiple Choice

The core of the Sun reaches temperatures up to...

• 5 million degrees celcius

• 10 million degrees celcius

• 10 billion degrees celcius

• 15 million degrees celcius

Multiple Choice

The radiative zone is ______ the core.

• the same temperature as

• hotter than

• cooler then

The Sun’s outer layers are called its atmosphere. These layers are much less dense than the interior. The atmosphere generally becomes hotter and less dense as you move outward.

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The Sun's Atmosphere

Visible light moves by radiation out into space from the photosphere. It takes about eight minutes for the light to reach Earth. Since the photosphere is the layer you see in photographs of the Sun, it is often called the Sun’s surface. Convection currents beneath the photosphere cause it to have a bumpy texture.

Photosphere

The chromosphere is the thin middle layer of the Sun’s atmosphere. It gives off a pinkish light.

Chromosphere

The Sun’s outermost layer is called the the corona, which varies in shape, extends outward several million kilometers. Both the chromosphere and the corona are much hotter than the photosphere. However, they have such low densities that you can see their light only during a total eclipse of the Sun, when the Moon blocks the much brighter light from the photosphere.

Corona

Multiple Choice

Which layer gives off a pinkish light?

• Photosphere

• Chromosphere

• Corona

Multiple Choice

What leads to the bumpy surface of the photosphere?

• Uneven rock layers

• Convection currents underneath the photosphere

• Tetonic plate movement

• Convection currents in the core

Labelling

Label the 6 layers of the sun.

Drag labels to their correct position on the image

Core

Corona

Convection Zone

Photosphere

Radiative Zone

Chromosphere