Halloween is just around the corner, and it seems a spooky coincidence may just provide us with the perfect decoration for our parties... and it's free! On October 31st, 2020, we'll be witnesses to a blue moon!First of all, it is important to explain what a blue moon is. It is a full moon, but not just any full moon. It is a ‘phenomenon where two full moons occur in the same calendar month,’ as explained by Sciences et Avenir. In other words, it is the second full moon in the same month, and the thirteenth full moon of the year.This phenomenon occurs approximately every three years. But careful, this name does not correspond to the colour of the Moon, but it refers to the expression ‘blue moon,’ which means something that happens very rarely. View this post on Instagram Bluemoon A post shared by @ kwonyongjae_97 on Sep 14, 2020 at 5:28am PDT By pure chance, the only blue moon of 2020 will shine on the night of October 31st, the night of Halloween! That night’s moon will be like no other, making for an unusual evening. Everything is in place for a terrifying Halloween this year! For your information, the next Blue Moon will occur on August 31st, 2023.The year 2020 is decidedly rich in events concerning the moon: last June, a full strawberry moon was visible in the sky, as well as two supermoons.