AstroEvent of the Week: 04.06.09: An Easter Full Moon.

A Paschal Moon on Maundy Thursday! (Photo by Author).

This months’ Full Moon on Thursday is a special one. Known variously as the “Pink” or “Egg” Moon, April’s Full Moon also shares the distinction this year of being an Easter or Paschal Moon, as well. Current tradition sets Easter in the Christian calendar as the first Sunday after the first Full Moon after the Vernal (or Spring Equinox). All this means is that the date of Easter is highly variable, falling as early as March 22nd, a day after the date set by the church as ecclesiastical equinox, March 21st. In fact, the equinox can vary by a day or two! For this to occur, the Full Moon, and Sunday all must fall in quick succession, which last occurred in 1918. The latest date Easter can fall is April 25^th, as it will do again in 2038. Numbers are fun stuff! This was first established as a convention by the First Council of Nicaea in 325 A.D., and was the driving force behind Pope Gregory’s reform of our calendar 1582. This particular Full Moon is also sacred to the Jewish faith as heralding the beginning of Passover on sunset on the 8^th, the marking the start of Theravada New Year on the Thai Buddhist calendar, and Hanuman Jayanti on the Hindu time line, as well. A holy Moon, indeed! The exact timing of the Easter Moon is April 9^th, 10:55 AM EDT Local. And you thought it was just about an egg laying rabbit…Happy Easter!

This week’s Astro-word of the week is synodic month. The ecclesiastical month that the church uses to base its calculations for Easter on assumes the Full Moon falls 14 days after the New, which is in turn based on the synodic month. This is the time it takes from lunation to lunation, or the time it takes the Moon to return to the same phase. Its important to note that a phase like New or Full is just an instant in time… common vernacular is to say “the Moon is Full tonight…” when what we really mean is the Moon passed (or will pass!) The instant of “Fullness” on that date. The synodic month is currently measured as 29 days, 12 hours, 44 minutes and 2.9 seconds.