A Black Moon rises Aug. 23, though you won't see it. Its timing makes it a rare lunar event. On Aug. 23, the night sky will play host to an unusual lunar event known as a Black Moon. While you won't actually see anything unusual (in fact, you won't see the moon at all), this event is still exciting because of its rarity.

Saturday's new moon is a seasonal "black moon" — a rare phenomenon that occurs once every 33 months. Here's what that means and why it's a great night for stargazing.