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.
Why shouldn't you stare at the sun?
Sun exposure can damage not only the skin, but the eyes, too. Even one day in the sun can result in a burned cornea (the outermost, clear membrane layer of the eye). Cumulative exposure can lead to cataracts later in life (clouding of the eye lens), which can actually lead to blindness. The best way to protect your eyes is to wear sunglasses with a high level of UV protection.
Here are a few fun activities to really bring the power of the sun home!
Make a sun oven: Take a cylindrical tube (like an oatmeal box), and cut it in half lengthwise. Line the inside of the box with aluminum foil, with the shiny side facing up. Place your sun oven outside in a bright, hot area, and you’re ready to cook! Place a hot dog in it and lunch will soon be ready! Sun tea would be a great accompanying drink.
Sun Painting: Take some dark colored construction paper and place it outside in the bright sun. Place some interesting objects – leaves, rocks, twigs, even small household items – on the paper, and leave them alone for a few hours. Then remove the objects to see what the sun has painted!
Sun for the Garden?: Plant two similar sun-loving plants in small pots. Place one in a sunny location, and the other in a dark spot, like the garage or a tool shed. Water both each day, and compare the results over several days. This activity is great for teaching how necessary sunlight is for plants to grow.