1. Our Star
The sun is a star, just like the other ones you see in the night sky.
It is a yellow, middle-sized star.
It seems bigger than other stars do, but that is just because it is closer to Earth.

2. Our Star The sun is the closest star to Earth.
Even though it is the closest star to Earth, it is still very far away.
The sun is 91 million miles away from Earth.
In star distances, 91 million miles away is not very far at all.
Proxima Centauri, the next closest star after the sun, is 26 trillion miles away.

3. Our Star
Fun Fact:
Most stars are far away, so we can’t feel their light and heat.
But the sun is close to Earth.
It gives us the light and heat we need to live.

4. We Need Sunlight
Without the sun, our world would be wrapped in darkness.
Trees, grass, and other plants would not grow.
Animals and people would have nothing to eat.

5. We Need Sunlight Fun Fact:
The sun gives of 40,000 watts of light from every square inch of its surface.
Imagine fitting 400 light bulbs in a square that is only one inch long on each side!

6. We Need Sunlight
Without the heat from the sun, the Earth would be a very cold place.
Oceans and lakes would turn to ice.
The air would be very still and too cold to breathe.

7. We Need Sunlight The sun creates our weather.
Oceans, lakes, and rivers take in energy from sunlight.
This energy heats the water.

8. We Need Sunlight
When the water gets warm, some of it turns into vapor.
The vapor rises and mixes with the air.
As water vapor cools, it turns into tiny droplets that form clouds.
These clouds can bring rain or snow.

9. We Need Sunlight The land also absorbs sunlight’s energy.
As the land warms up, it heats the air above it.
Warm air rises and expands.
As the air moves, a breeze is formed. These winds rush across lakes and fields, cities and mountains.

10. Night and Moonlight Stars cannot be seen during the daytime.
The sun shines more brightly than the stars and hides them.

11. Night and Moonlight At night, the moon gleams with a pale, cool glow.
Moonlight really comes from the sun.
Part of the moon’s surface faces the sun.
That part of the moon catches the sun’s light. Some of the light bounces off the moon and shines down to Earth.