Celebrate Summer: Learn About the Sun!

Humans for thousands of years have stood in awe of the sun, tracking its changes, celebrating its warmth each spring, and even worshiping and sacrificing to it.

We know a lot more about the sun today! Scientists have recently learned much more since the launching of SOHO (The Solar and Heliospheric Observatory) in 1995. Now we know more than ever about this huge ball of gas that warms us, causes our seasons to change, and allows our food and everything else on earth to grow.

As we enjoy hot summer days in the Northern Hemisphere, here are the answers to a few questions your child might be asking you about the sun... just in time for summer.

What is the sun?

The sun is actually a normal star, just like the many millions of other stars in our Milky Way galaxy. The reason it appears so much brighter and hotter to us earthlings than any other star is because it is by far the closest star to us. It’s the same idea as if you saw one car’s headlights shining up close, and another a couple of block’s away. The closer one would appear much bigger and brighter. So it is with our sun.

How big is the sun?

Our sun is much, much bigger than the Earth. It’s radius is 696,000 km, compared to the Earth’s radius of 6, 376 km. About 1 million Earths would fit inside our sun! It is also very far away – 150 million km, or 93 million miles, from the Earth. This is actually pretty close in outer space standards, when you consider that the next closest star is about 25 trillion miles away!

What's the sun made of?

Even though it is made up entirely of gases, the sun has a powerful gravitational pull that keeps the earth as well as the other planets in our solar system spinning in their orbits, and literally keeps them from flying off into outer space!

Why is the sun hotter in the summer?

Thanks to the perfect harmony between the sun’s warmth, its gravitational pull and the Earth’s rotation as it orbits the sun, we have changing seasons, and even the alternating cycle of day and night, months and years. Without the sun, no life on Earth could exist.

In summer, the sun is higher in the sky than it is during the other seasons. Because it is higher, the sun’s rays hit the earth at a steep angle. The light doesn’t spread out very much, so the maximum amount of energy hits any given spot. The long daylight hours also allow plenty of time for the sun to warm the earth, which causes the days to be hotter during the summer than other months.

Why do we have sunsets?

The sun emits light of all different colors that combine to make white light. During the day, when the sun is high in the sky, our atmosphere scatters the sunlight, and the result is a blue sky and a whitish-yellow sun. At sunset, the light is scattered even more because the sun’s light has to pass through more atmosphere to get to our eyes. This extra scattering of light makes the sun (and sky) look more reddish. Smoke or dust particles in the air can also enhance the scattering, affecting the color.