With just a few common household items, you can make a pinhole projector to view the upcoming solar eclipse safely and indirectly.
Although a total solar eclipse will be visible across only a small portion of the United States, everyone across the country will be able to view a partial solar eclipse, weather permitting.
A pinhole projector is one of many ways to view the partial phases of a solar eclipse indirectly, meaning that spectators can still see the eclipse without looking at the sun.
“You should never look at the sun directly without equipment that's specifically designed for looking at the sun,” NASA said.
The most popular way to view a solar eclipse safely is with the help of specially-made eclipse glasses, but those that cannot get a pair by Aug. 21, a pinhole projector is the next best thing.
Even those with a pair of eclipse glasses may want to make a pinhole projector out of common household objects as it can be a fun experiment to try during the eclipse, especially for children.
There are different types of pinhole projector, but the simplest design only requires two sheets of paper and a pin or thumbtack.
Making the pinhole viewer
For the basic form of the pinhole projector, all you need to do is to use the pin or thumbtack to poke a hole in the center of one of the pieces of paper.
Set it up and test how it works
You should make sure to test out your pinhole projectors before Aug. 21 to ensure that you know how to use them properly ahead of time.
To use the basic pinhole projector, place the second piece of paper on the ground and hold the piece of paper with the hole in such a way that its shadow is cast onto the ground.
In the center of the shadow, there should be a circle of light made by the hole in the paper.
On the typical day, the sunlight shining through the small pinhole will appear as a circle.
However, during the partial solar eclipse, the sunlight will appear as a crescent that matches the current phase of the eclipse.
There are different types of pinhole projectors that can be made, but they all follow the same concept of viewing the sun indirectly.
One fun variation is to punch many holes in a piece of paper in the shape of words, numbers or animals. This can result in unique designs that will be comprised of dozens of little crescents during the partial eclipse.
I had my kids and niblings make some fancy pinhole projector cards. Here's my nephew's: pic.twitter.com/K7K7KveMRW
— Emily Lakdawalla (@elakdawalla) July 27, 2017
A more complex type of pinhole viewer requires an empty cereal box, a piece of paper, scissors and some aluminum foil.
NASA also has 2D and 3D printable pinhole projectors that are in the shape of each state in the country, as well as Washington, D.C., Puerto Rico and the U.S. Virgin Islands.