Those looking up at the sky on Tuesday night might witness a blue moon. Here's what you should know about this famously rare astronomical event.
When the full moon rises tonight (Aug. 20), it will technically be a Blue Moon, but not for the reason you might think.
The Blue Moon tonight is not the second full moon of August, but actually gets its name from a relatively obscure rule of astronomy. And there are a few other details about the full moon that might surprise you.
So to celebrate the Blue Moon, here are five amazing facts about this month's full moon:
1) It's not really blue: Okay, so not really a newsflash, but the Blue Moon's name actually has nothing to do with color. Occasionally, the full moon can take on a reddish pallor, but today's full moon is not related to the actual color of Earth's cosmic neighbor. The moon can appear blue in color if a forest fire or volcanic eruption litters the upper atmosphere with ash or smoke. A volcanic eruption gave the moon a bluish tint from the perspective of many people on Earth in 1991. [Blue Moon Explained (Infographic)]