the.com/moon phases
the moon has no light of its own, it is just showing off the sunlight it steals.
means the changing shapes of the moon we see each month, caused by how much of its sunlit half faces earth.
from the word month literally comes from moon: ancient calendars were built by counting lunar cycles, roughly 29.5 days from new moon to new moon, long before anyone measured a solar year.
cycle length29.53 days on average, called a synodic month
tidal linkspring tides happen at new and full moon
same facewe only ever see one side of the moon
not shadowphases are angle, not earth blocking sunlight
for instance
harvest moon — full moon nearest the autumn equinox, lights up farmers for extra harvest hours
blue moon — second full moon in a calendar month, happens about every 2.7 years
supermoon 2016 — nov 14, 2016 full moon was closest to earth since 1948
islamic calendar — entirely lunar, months start at first sighting of the crescent