Okay, so you missed your opportunity to buy legit solar eclipse glasses for your family and you may have even missed the opportunity to get free solar eclipse glasses in select locations.

That doesn’t mean you should scorch your retinas for life for a few hours of once-in-a-lifetime science coolness. Just…make your own eclipse viewer!

Check out this easy (really!) DIY solar eclipse viewer tutorial on YouTube from NASA and breathe easy. All it requires is stuff you have in the house anyway: A cereal box or two, a little tin foil, some paper, and tape.

Related: How to know how much of the eclipse you’ll see based on location

 DIY cereal box eclipse glasses tutorial from NASA. Easy! | via Brian Kamoie on Twitter

The results! DIY cereal box eclipse viewers via FEMA administrator @Brian Kamoie on Twitter

Be sure to follow the instructions to a tee — NASA even clarifies some questions in comments. Like you want to use foil and a nail — not paper and scissors — so you get the cleanest pinhole.

Another tip: the smaller the hole, the sharper the image.

And of course, be sure you’re looking through that hole with the sun behind you. It’s not a telescope.

Happy — and safe — eclipse viewing!