If you are a sky-watcher or a horror geek, you are in for a treat tonight as a rare phenomenon is about to show up on the night sky. On Halloween night, a rare blue moon, which hasn't shown itself on this special day since 2001, will descend upon us to add to the eerie atmosphere that surrounds Halloween.

What is a Blue Moon?

But hold your horses. Let me explain. A blue moon isn't literally a blue- coloured moon. It looks like a typical full moon but it is still a rare phenomenon that occurs every two to three years. According to NASA, a blue moon occurs when there are two full moons in a calendar month, a phenomenon that coincides with Halloween only once every 19 years. If you are planning to lose out on this opportunity, keep in mind that you may have to wait till 2039 to witness a similar episode again.

This particular blue moon is also called the blue hunter's moon because the Harvest moon fell on October 2 this year. The hunter's moon is named so because the full moon illuminates the field for hunters to catch their prey at night and stock up for the long winter ahead.

Will you be able to see it?

According to FarmersAlmanac, the Halloween blue moon in 2001 was only seen in the Central and Pacific Time zones. But this time around, anyone from any time zones will be able to witness it, making it even rarer. Actually, the last time the whole world saw a full moon on Halloween together was way back in 1944!

The full moon has been an efficient tool for years in folklores and pop culture to spook audiences and signify the presence of paranormal beings, giving Halloween enthusiasts more reason to look forward to the spookiest day of the year.