On August 21, 2017, the United States will witness a solar eclipse. Parts of fourteen states will experience a total solar eclipse, but people in every region can observe at least a partial eclipse of the sun.
What is a solar eclipse and how can parents explain this concept to their kids in a child-friendly way?
Solar eclipses happen when the Moon gets in between the Earth and the Sun in just the right spot to block our view of the Sun from Earth. Solar eclipses happen because of an amazing cosmic coincidence: the Moon is way smaller than the Sun, but it is also much closer to the Earth than the Sun is. So the Moon and the Sun just happen to look about the same size from our point of view when we see them in the sky. (Never look directly at the Sun, of course!) Therefore, as the Moon orbits the Earth, on rare occasions it can appear to block out the Sun.
Imagine you have a tennis ball, a beach ball, and a golf ball. Let’s pretend the beach ball is the Sun, the tennis ball is the Earth, and the golf ball is the Moon. Imagine the tennis ball and golf ball are really far away from the beach ball. When all three line up, sometimes it can look like the golf ball perfectly blocks out our view of the beach ball, even though the beach ball “Sun” is a lot bigger than the golf ball “Moon.”
How can parents and kids safely observe the eclipse together?
Because the Sun is so bright, it can damage your eyes if you look directly at it. So it’s important to understand how to safely view the total solar eclipse. The good news is there are lots of ways to do this. NASA’s eclipse website and the Exploratorium’s website are great resources. Here are a few tips:
- Use your hands or even a tree to view images of the Sun on the ground. Loosely interlace your fingers so that sunlight can shine through them, then watch the images of the Sun that you see on the ground. Or you can look at the images of the Sun on the ground that shine through the holes in the tree’s leaves. Sometimes it helps to put a white piece of paper on the ground to see the images better.
- Build what is called a “pinhole viewer”for looking at an image of the Sun that is dim enough to view safely. The simplest way to do this uses two sheets of stiff white paper and a pin. (You can see an example from NASA here, at the bottom of the page.) Punch the tiniest hole you can make with the pin in one sheet of paper, then go outside and aim the hole at the Sun — but don’t look at the Sun, either through the hole or directly. Move the other piece of paper up so that the image of the Sun falls on it, and move that piece of paper back and forth until the image looks crisp and sharp. You can also build fancier versions of this type of pinhole viewer using cardboard tubes or boxes.
- Get special eclipse-viewing glasses. These are NOT sunglasses, which will not protect your eyes adequately. Make sure they meet the proper standard for eclipse-viewing glasses. (There are currently five manufacturers that have certified that their eclipse glasses meet the ISO 12312-2 international standard for such products: American Paper Optics, Baader Planetarium [AstroSolar Silver/Gold film only], Rainbow Symphony, Thousand Oaks Optical, and TSE 17.)
How can parents help kids get the most out of this experience? What can they look for together and talk about together on this special day?
It’s fun to try to make your own eclipse using a flashlight in a dark room and things like beach balls and tennis balls to represent the Sun, Earth, and Moon. This type of modeling helps kids understand the basic position of where everything has to be for an eclipse to happen.
What you’ll see during the eclipse depends on where you are and how you are viewing it. The path of totality (where the Moon completely blocks out the Sun’s light) runs right through the middle of the continental United States, but it is pretty narrow. Outside of that, it’s possible to see a partial solar eclipse, where the Moon partly blocks the Sun. Regardless of where you are, the main thing is to get outside and try to see it for yourself (safely, of course!).
What do you love about eclipses?
As a scientist, I’m excited that solar eclipses offer us the opportunity to get a rare glimpse of the structure and composition of the super-hot gases in the Sun’s corona, or outer atmosphere. The Sun’s light is so bright that it makes it hard to see the gases coming off of the Sun, and total solar eclipses help us see them. This helps us understand our Sun’s complex structure and how its activity influences our lives on Earth.
But perhaps most important, solar eclipses offer us a powerful reminder of our place in the cosmos as we go about our daily lives: we sit on a small planet speeding around a gigantic Sun, whirling through the galaxy. The amazing thing about science is that we can now understand this phenomenon, predict when it happens, and learn from it.