The black moon is occurring this weekend, but it won’t be visible from Earth. Here’s everything you need to know about the celestial event.

You've no doubt heard of supermoons, blue moons, mini moons and blood moons, but have you ever heard of a black moon?

A rare black moon will happen tonight Aug. 22-23. Don't worry too much if you miss it, although it won't happen again for almost three years: A black moon is invisible. There will be a moon-sized dark spot in the sky, though, which makes conditions perfect to to spot other stars and planets or even the Milky Way.