India, May 29 -- In a recent Instagram video, shared by The Museum of Science breaks down why the upcoming blue moon is rare and why the moon will not actually turn blue.

"Once in a blue moon" is usually just a saying people use for something that rarely happens. But on May 31, the phrase will match a real event in the night sky.

A rare blue moon is expected to appear, catching the attention of skywatchers, moon lovers, and astrology followers. If you are imagining a glowing blue moon hanging in the sky, there is one thing to know first. That is not what a blue moon means.

A blue moon has nothing to do with the moon's colour.

According to the Museum of Science, a blue moon happens when two full moons fall within the same calendar mont...