Worm Supermoonbr to Illuminate thebr Sky This Week On March 9, the Full Worm Moon,br the first supermoon of 2020, willbr be visible in the night sky. A supermoon occurs whenbr the moon is on its closestbr orbital approach to Earth, orbr within 90 percent of perigee. According to NASA, although thebr true full moon will only be on Monday,br the moon will continue to appearbr full until early Wednesday. The name, Full Worm Moon, is derivedbr from the way in which Native Americansbr would use the moon to track the seasons. In this case, the March full moon wasbr associated with the softening of the ground,br which caused earthworms to begin to appear. The Full Worm Moon is also referred tobr as the sugar moon, because of the arrivalbr of spring and the Lenten moon, as it occursbr during the Catholic season of Lent. 2020 is expected to have up to four supermoonsbr total, with the next supermoon set to appear on April 7.