Palm Sunday, March 28 brings us the first full moon of the new spring season: the Paschal full moon. The official moment that the moon will turn full is 2:48 p.m. EDT (1848 GMT).
Traditional names for the full moons of the year are found in some publications such as The Farmers’ Almanac. We also published the full list of full moon names here on Space.com earlier this year. The origins of these names date back a few hundred years to Native American tribes, though they may also have evolved from old England or, as astronomy author Guy Ottewell, suggests, “writer’s fancy.”
Traditionally, the March full moon is known as “Worm Moon,” supposedly because when the ground softens the earthworm casts reappear, inviting the return of the robins. Other lunar monikers included “Crow Moon” (when the cawing of crows signals the end of winter), “Crust Moon” (because the snow cover becomes crusted from thawing by day and freezing at night) and “Sap Moon” (marking the time of tapping maple trees).
The first full moon of spring is also designated as the Paschal Full Moon or the Paschal Term — 14 or 15 Nisan on the Jewish Calendar, which is also marks Pesach, or Passover. Easter is observed on the Sunday after the Paschal Full Moon. If the Paschal Moon occurs on a Sunday, Easter is the following Sunday.
March full moon 2021: Catch the big ‘Worm Moon’ (and 1st ‘supermoon’ of the year) on Sunday
So according to the current ecclesiastical rules Easter is to be celebrated on Sunday, on April 4. Interestingly, Easter can fall as early as March 22 and as late as April 25. Pope Gregory XIII decreed this in 1582 as part of the Gregorian calendar. So, by these standards, Easter is coming a little earlier than usual in the calendar