We bet you’ll learn something, too, in this neat, illuminating (ha!) lesson about the color of the sun. We had the pleasure of hosting a similar activity at our local elementary school along with help from the Smithsonian National Air and Space Museum. The 6-8 year olds seemed to engage with this activity the most, although all ages enjoyed it. The key to this activity: allowing children to discover the answers themselves.
You will need a sunny day, a piece of white paper, a flashlight, and various colored translucent plastic or tissue papers. If you have them, you can do the second part of the lesson using prisms. Have some crayons and drawing paper handy if you want the kids to draw the spectrums they see.
What Color is the Sun?
First, ask your children what color they think the sun is. Many will tell you yellow, or perhaps other colors. Some may tell you it is white. If you are working with a group, make sure everyone has a chance to guess. Next, wrap the lit end of a flashlight with colored tissue paper or arrange a piece of colored plastic so that the light will shine through the color.
Let’s say it is wrapped in pink tissue paper. Ask what color they think the light from the pink flashlight will be. Then shine it on a white piece of paper and observe the pink light on the paper. Do the same with other colored tissues, observing with the children how the color of light on the paper is the same as the color shining from the flashlight. Again, be sure each child has a chance to describe the colors they see.
Now, explain that you are going to try to figure out what color the sun is.
Take the white paper and put it in the sunlight. Ask what color the light on the paper is, and observe with the kids that it is white. Then ask, “So, if the light on the paper is white, the sun must be…?” Everyone will be very excited to tell you that it is white!
Next, you can pull out some prisms and let the kids play with them a bit. Discuss how the prism is breaking up the sunlight into all of the colors that are in sunlight. If you have time, the kids might like to draw what they see. Note how yellow is the strongest color in the spectrum and explain that while sunlight looks white, it is, in fact, just a little tiny bit yellowish, and that is evident in the extra strong yellow in the spectrum. The sun is classified as a yellow dwarf star.
Older children might like to talk a bit about how at dawn and dusk, the atmosphere interferes with the sunlight and lets just the longest light waves – the reds, oranges and yellows – through to our eyes.
A note about prisms: In our experience, kids love to play with prisms. But for younger children, it can actually be quite difficult to angle the nice prisms correctly and get a spectrum to show. If you have an older child and want to get a full set, by all means go ahead and have one at hand. They really help visualize light refraction and scattering if you set them up in sequence. But you can also get a lot out of a very simple and cheap teardrop-style prism that throws a lot of rainbows out all over the place and is very satisfying for younger children.
If you really want to get awesome, get a keplerian telescope, which allows multiple children to easily and safely view the sun, including large sunspots and the corona. The device is simple enough for children to adjust (and because of the movement of the Earth, they will have to adjust it every few minutes as it moves out of the viewing area). If you and your children get very excited about astronomy and want to take on a larger activity, consider making your own.