Our Energy Source, the Sun!Lesson 19

What is the sun?

Sun: a star that is the source of light and heat for the planets in

the solar system.

Our sun is a member of the Milky Way Galaxy and is believed to be

over 4 billion years old.

The sun is the center of our solar system. It is the largest object

in our solar system.

The sun is actually a star. Our sun is considered a medium-sized star.

A star is a ball of burning gases, mostly hydrogen and helium.

A star shines or glows because of its gases. Stars give off light, heat

and energy.

Since the sun is a star you can describe the sun as a round ball of

hot gases.

The sun’s surface is always changing.

There are stars that are bigger, smaller, hotter, and cooler than our

sun. The sun is our closest star.

The Earth is very small compared to the Sun. More than a million

Earths could fit into the Sun.

All life on Earth depends on the Sun for light, heat and energy.

The sun is the Earth’s only source of heat, light and energy.

The sun spins slowly as it moves around the galaxy.

All of the eight planets (and the dwarf planet Pluto) travel around the sun.

The time it takes a planet to travel around the sun is one year. This journey the planets take around

the sun is called an orbit.

Let’s watch this video about the planets orbiting the sun.

• http://www.youtube.com/watch?v=WgLviwOsok4

The sun and the stars make their own light. The moon does not

make light. It reflects light.

Stars and the sun produce light, heat and energy. The moon,

planets, comets, meteorites and almost everything else in space do not produce heat, light and

energy.

The sun shines all the time.

Yet the sun can only be seen in the daytime. You can only see the sun when the side of the Earth you are

on is facing the sun.

The moon can be seen sometimes at night and sometimes during the

day.

A solar eclipse is when the moon comes between the sun and the

earth.

Now let’s see what you remember. Take sometime to answer The Sun

worksheet. I will read the questions to you and you take the

time to answer the questions. After you finish answering the

questions I will go over the answers with you.

Today we learned about the sun. We could not survive without the

sun’s light, heat and energy.

In our next lesson we will learn more about the stars.

Keep observing the world around you!