Solar Eclipse Viewing With a Disco Ball

I am about to blow your mind. As a longtime astronomer and viewer of many eclipses - both solar and lunar - I have seen and used a wide variety of methods for eclipse viewing, everything from pinhole projectors to solar telescopes. My all-time favorite is one I learned about from a site I used to contribute to, Universe Today, a couple of years ago during the 2023 partial solar eclipse.

Using a disco ball is one of the best ways to view and enjoy a solar eclipse, and it is easy and cheap to set up and use, especially in large group settings. Get your disco playlist ready to learn how to have an eclipse viewing experience that is out of this world!

This is a short list of supplies and easy to do, all you need is:

1. Solar eclipse, partial or total
2. Disco ball
3. An interior space with a window that faces the sun OR a shaded exterior space such as a shed canopy tent with walls
4. Good weather
5. Optional: solar eclipse glasses
6. Mandatory: disco music

I have to get this out of the way: NEVER, EVER look at the Sun directly, or through a telescope or binoculars. You need to project the image, use certified equipment such as solar eclipse glasses or proper solar telescope equipment to safely view the sun. This eclipse viewing method is by far one of the safest, but always use caution and common sense when doing solar viewing.

The first thing you will need to do is find out when the next solar eclipse in your area will take place, or where you might travel to view one. Eclipses aren't as rare as people typically believe, but they do happen at various locations around the world and our Earth has a lot of surface area that is water so you will either have to get lucky or plan a trip.

There are a plethora of resources on the internet to determine this, I will typically use www.timeanddate.com. Organizations like NASA, The Astronomical Society of the Pacific, and The Planetary Society all have resources on upcoming eclipses and times, and alternative ways to view or project them. It's important to find the exact times of the eclipse so you can get everything set up at your location. I'll note that many of these resources focus on total solar eclipses, but annular and partial eclipses are also worth viewing and traveling for.

I am very excited to travel to Iceland with a disco ball in hand for the upcoming total solar eclipse in August of 2026!

Astronomy is one of the most weather-dependent hobbies that exists - if it is cloudy, you can simply be out of luck. Because eclipses last a short time - a few hours for a long partial eclipse, a couple of minutes for totality during a total eclipse - it's important to determine the weather for your location at the time of the eclipse. Regular weather forecasts are just okay for this, so you should explore forecasts that are intended for astronomers.

My go-to resource is the Clear Sky Chart. You can input your location and get a forecast of cloud and smoke coverage, an idea of times that are dark (for night-time astronomical viewing) and other information. They have an app as well as their site online, and a pretty good distribution of sites across North America.

Other apps that are useful are Astrospheric and Ventusky. I use Ventusky as my primary weather app either in the US or abroad, and their cloud forecasting rivals that of apps that are intended for astronomical viewing and they have forecasts for sites all over the world. If you have a favorite astronomical forecast resource for destinations outside the US, please leave a link in the comments.

It is highly advisable to be ready to travel at a moment's notice during an eclipse. If you drive 40 or 50 miles somewhere else in the path of the eclipse, you might get better weather. The benefit of using a disco ball for viewing is that it's a highly flexible piece of equipment to set up for viewing no matter where you end up!

If you already have a disco ball, pat yourself on the back for how hip you are. If not, get whatever you can find - we borrowed a big 12" disco ball with batteries and a motor that could spin it in 2023, but even the smallest of them would work. Something like an 8" disco ball like this one from Amazon would be fine, but also check local thrift stores and party supply stores for one. If it's missing a couple of mirrors it really does not matter, and even tiny little trinket ones that are about 2" in diameter should work fine, they will just project fewer images because they have fewer mirrors.

All you will need to mount your ball is a piece of rope or string, and somewhere to hang it from. You can get fancy and put it on some sort of wooden stand, but this is not necessary by any means.

The most important part of viewing an eclipse with a disco ball is determining where to place it so that you can see the projections. It needs to reflect the sun's image into an area that has shade - you won't be able to see the reflected images well or at without some sort of shade. If you are in a building, find a window that faces the sun and try setting up the disco ball a couple of days in advance of the eclipse to determine whether it will project the image properly. It will show the image of the sun as a bright dot, not the cool half-moon shape that you see during the eclipse as shown here.

If you are outdoors, set up the ball so that it projects into the shade of a tree, underneath the canopy of a tent or other shaded structure. Again, it can be helpful to set this up a day or two in advance of the eclipse on a clear, sunny day to determine if the location you've chosen will work.

I helped run an astronomical observatory at the time of the 2023 eclipse, and we were fortunate to have the benefit of our telescope's rotating dome. It was easy to attach the disco ball to the slit in the dome, raise it up, and point it exactly where we needed it to be to project the image. The interior of the observatory and the dome itself made for a very immersive experience. If you are associated with an observatory or astronomy club, I highly recommend this method, but it's not necessary to be able to use the disco ball for solar eclipse projection.

Once you have your site selected, your disco ball in hand, and the weather is clear and it's time for the eclipse you are ready to party! Get your disco soundtrack ready and enjoy the show. Because the shape of the projected image of the sun changes over the duration of the eclipse, you will see a smaller shadow of the moon at the start of the eclipse, with a more pronounced shadow later during the event. I find it fun to take observations or pictures of how this change occurs during the eclipse.

It's helpful to have a pair of solar viewing glasses on hand to look at the Sun directly (and safely) during the event. See below for other methods of viewing the eclipse safely.

When I have used a disco ball to view the eclipse it is simply magical and immersive - it is so fun to be surrounded by tiny images of this astronomical phenomenon, it adds a really fun layer to observing the event, and playing disco music during the eclipse is probably the only time I ever listen to or enjoy that style of music!

It is relatively easy to project the image of an eclipse to view the shadow created by the Moon as it goes in front of our Sun - all you need is a piece of paper with a small pinhole in it, called a "pinhole viewer". This works much like a pinhole camera, where the light rays go through the hole and are flipped upside-down in a projected image a few inches or feet from the hole (depending on its size).

Other methods of projecting the eclipse that are neat are using a collander or straining spoon with a bunch of holes in it, or looking at the projected image of the eclipse in the shade of a leafy tree. For other, boring ways to view the eclipse (if you happen to hate disco...) see this video from NASA.

Each of the mirrors on the ball is reflecting a distinct image of the Sun - during normal times when there is not an eclipse, you're seeing a full disk reflected on whatever surface the projection lands on. This same thing happens at disco events or concerts, where the mirrors are reflecting an actual image of the lights shined on them - it's just too hard to see any details in the final projected image.

As the Moon obscures part of the Sun during an eclipse by traveling in between our Earth and the Sun, the image of the Sun becomes a crescent, and you see this detail in the projected image.

If you want to dive deeper into the science and optics of using a disco ball for eclipse viewing, I highly recommend this scientific paper attached. Citation: Cumming, R., Pietrow, A., Pietrow, L. et al (2024). Why every observatory needs a disco ball. Physics Education, 59(2). http://dx.doi.org/10.1088/1361-6552/ad1fa0