Our Moon's appearance changes nightly.
This time-lapse sequence shows
what our Moon looks like during a
lunation, a complete lunar cycle.
Moon orbits the
the half illuminated by the
first becomes increasingly visible,
then decreasingly visible.
always keeps the same face toward the Earth.
The Moon's apparent size changes slightly, though,
and a slight wobble called a
libration is discernible as it progresses along its elliptical orbit.
cycle, sunlight reflects from the
at different angles, and so illuminates different features differently.
lunation takes about 29.5 days, just under a month