By Bruce McClure and Larry Sessions
Friday, May 8, 2009
Your calendar might say that full moon comes on May 9, but it’s a very full-looking moon that’ll rise over the eastern horizon on May 8 at around sunset. At the meridian of Greenwich, England — the home meridian of Universal Time — the May full moon happens at 4:01 a.m. Saturday morning. That’s 10:01 p.m. tonight in the U.S. Mountain Standard time zone.
So if your calendar uses Universal Time, which many do, it’ll give May 9 as the date of full moon. But the moon is really closer to full tonight than tomorrow night.
In the northern hemisphere, we call this May full moon by the name Planting Moon or Milk Moon. It’s in front of the constellation Libra — not far from Libra’s brightest stars — Zubenelgenubi and Zubeneschamali. Like many star names, these names are derived from the Arabic. The names mean the Southern Claw and the Northern Claw, respectively.
Claws for a scale? No. But scorpions do have claws, and these two stars were originally part of the constellation next door, Scorpius the Scorpion. The Chaldeans and Greeks knew them as such. But to honor Julius Caesar, the Romans turned these stars and some others into an image of the Emperor holding the scales of justice. Interestingly, it is the only constellation of the Zodiac, or Circle of Animals, that is not an animal.
Like most other bright stars visible to the eye, Zubenelgenubi and Zubeneschamali are larger and brighter than our sun. They are about 77 and 160 light years away, respectively.
Full moon names — www.EarthSky.org/FAQ/full-moon-names
Universal Time Coordinated (UTC) — www.EarthSky.org/article/universal-time