Here's what to know. When the moon is nearly between Earth and the sun, one side of the moon faces the sun, and that side is illuminated, but the side the Earth sees is dark. This is called the new moon phase of the lunar cycle — when the moon isn't visible at night.

A 'black moon' is set to be visible in our skies come Friday 22 August, though many have been spooked by the prophecy behind it. The rare astronomical event only comes around every few years, but despite this occurrence, people have started to speculate about what this may mean for humanity.

While scientifically intriguing, the Black Moon isn’t visible at all, which is part of what’s made it the subject of ominous folklore. The term refers to the second new moon occurring within a single calendar month, a phenomenon that happens approximately every 33 months.

A seasonal black moon, to appear on August 22 or 23, is the third of four new moons within an astronomical season

On Aug. 23, the moon will reach its new moon phase, and this one is special. It's a seasonal black moon, a rare event that occurs about once every 23 months. The next one won't arrive until Aug. 20, 2028, according to timeanddate.com.