What if the Moon was a Disco Ball?

Hey, Vsauce. Michael here. If we turned the Moon into a giant disco ball, day and night would not be a disco party. Instead of diffusely reflecting sunlight onto all of us, a mirror-tiled moon would reflect specularly. You would be lucky to momentarily catch a single reflected beam of sunlight.

Now, with the help of visuals by Nick from Yeti Dynamics, who you should subscribe to immediately, let's see what would occur if a disco ball Moon actually happened. Here's the Earth with an imaginary screen behind it, so we can track the path of reflections from a disco ball Moon. It's 3,012 mirror tiles are ten kilometres thick and between 100 and 150 kilometres across.

And, as you can see, the beams of sunlight they reflect would only intersect with Earth briefly and rarely - a few every month or so would race past at more than 20,000 kilometers a second. From the surface of Earth, they'd just be tiny flashes in the sky 0.1 percent as bright as the regular Sun and would last a fraction of a second. The Earth, Sun and Moon just aren't ideal locations for disco ball effects.

But, if our disco ball moon was closer and orbited Earth not 384,000 kilometers away but less than 450, as far as the International Space Station does, it would be torn apart by gravitational tidal forces. Shoot. Also, the Moon doesn't really rotate from our perspective like a fun disco ball. It liberates, but it's starting to look like instead of an awesome lunar party decoration, a disco ball moon would just be a lunar party pooper.

So, for the sake of investigation, let's allow this disco ball Moon to not be torn apart and allow it to spin in the sky. Now we're talking. Occasionally we would get glittery reflections of a dimmer image of the Sun. From the surface of Earth, this is what we would see. You know, being able to see Earth reflected is almost cooler.

It's like being a bacterium on a giant's face who's looking into a mirror. You can see the giant, but not yourself. It kinda makes you feel small. But it would be a great way to take planetary selfies. So, let's watch a mirror the width of the Moon orbit as close as the ISS does. From the surface of Earth, it would look like this. The strobe lights around the edge, by the way, are ten kilometres across. Pretty cool.

Now finally, let's take a look at the Moon as a rotating disco ball from low orbit. The Moon is not a disco ball and likely never will be. It's just a diffuse source of illumination. But it's illuminating in a different way to imagine what would occur if that actually happened. Woah. And as always, thanks for watching.