From Mashable · Lois Mackenzie · · 1m 20s
The Moon is just getting started again
A 5% sliver on September 13 is the opening frame of a cycle that runs about 29.5 days.
In brief
A 5% sliver on September 13 is the opening frame of a cycle that runs about 29.5 days. The Moon looks different each night because we see a changing slice of its sunlit half, and right now that slice is growing. Originally reported by Mashable.
Barely there tonight
On Sunday, September 13, NASA's Daily Moon Guide puts the Moon at 5% visible. A thin sliver, easy to miss if you are not looking for it.
“The Moon may be hard to spot right now, but that won't last for long.”
It grows from here
The Moon is in its Waxing Crescent phase, the start of a new cycle. A little more of it shows up each night from now on.
Mark September 26
The next Full Moon lands on September 26, about two weeks out. That is the peak of the cycle now beginning.
Why the shape changes
The Moon orbits Earth over roughly 29.5 days. What you see depends on where it sits relative to Earth and the Sun, and how much of its lit side faces you.
“The phase we see depends on where the Moon is in relation to Earth and the Sun.”
Eight stops on the loop
New Moon, Waxing Crescent, First Quarter, Waxing Gibbous, Full, Waning Gibbous, Third Quarter, Waning Crescent. Then it starts over.
Which side is lit
From the Northern Hemisphere, light builds on the right through the Full Moon, then drains from the right and hangs on at the left before going dark.
“A thin sliver of light remains on the left side before going dark again.”
The essence
The Moon looks different each night because we see a changing slice of its sunlit half, and right now that slice is growing.
