Generally, a Blue Moon marks the 2nd time a moon increases within the exact same month. However the moon getting here on Saturday (May 18) is May’s very first moon, so why are individuals calling it a Blue Moon?

The response involves an unknown guideline, according to Space.com, a sibling website of Live Science.

In this case, the May 18 moon– likewise referred to as the Complete Flower Moon– is called a Blue Moon since it’s No. 3 of 4 moons in a single season. Generally, seasons have just 3 moons each, Space.com reported. [Photos from the Moon’s Far Side! China’s Chang’e 4 Lunar Landing]

The spring season started on the equinox, on March20 That really night, a moon referred to as the Complete Worm Moon shone in the sky. After that, the Complete Pink Moon increased on April19 After this Saturday’s Blue Moon, the 4th, and last, moon of the season, the Complete Strawberry Moon, will light up the sky on June 17.

Then, spring will end on June 21, when the summertime equinox gets here.

This odd Blue Moon guideline states that when one season has 4 moons, the 3rd one need to be called a Blue Moon, so that the 4th moon can be called a “late moon,” according to Space.com.

However regardless of its name, this moon will not be tinted navy, aquamarine or cerulean. The moon appears blue just when the best climatic conditions occur in the world. For example, a huge volcanic eruption that launches a great deal of dust can make the moon appear blue to Earthlings, as can dust storms and forest fires.

You can see Saturday’s Blue Moon beginning at 5: 11 p.m. regional time (2211 GMT), so long as the skies are clear. To enjoy it live over the skies of Rome, tune in here

Initially released on Live Science