When is the best time to view the moon? Hint: NOT when it’s full!
It is a commonly held belief that most humans share that the best time to view the moon is when it’s completely full. But did you know that this is not correct?! Contrary to what logic might tell you, the best time to view the moon is NOT when it’s full or completely lit up! The actual best time for moon viewing is when the moon is only half full (also known as the First Quarter).
When is the First Quarter of the moon and what does it look like?
The moon’s First Quarter is approximately seven days after the new moon. (A new moon is the first lunar cycle – when the moon is not visible (in other words, when it’s completely in shadow).) A First Quarter moon will appear to be half full (50% lit on one side and 50% dark on the other).
Why is the moon best viewed during the First Quarter?
There are two main reasons the moon is better viewed when during the First Quarter.
First, it’s important to remember that the moon does not emit its own light, instead it reflects the light from the sun. When the moon is only half full (as happens during the First Quarter), sunlight does not directly reflect off the moon – instead, light hits the moon at an angle. If sunlight hits the moon directly (as it does when it is completely full), ever feature of the moon is highlighted in stark relief, resulting in a very two-dimensional appearance. If you were to therefore look at the moon when its full, yes, you’d be able to see it because it’s bright, but the craters and different features would be all washed out. When sunlight hits the moon at an angle however (as it does during the First Quarter), light and shadow make the craters, mountains, and rocks easier to see. They’ll look much more three-dimensional!
The second reason the moon is better viewed when only half full (during the first quarter) is because it’s plain and simple just not as bright. During the First Quarter, the moon is only halfway illuminated, and reflects back only a fraction of the light it would when it would be completely full. This makes it easier to see without squinting, filters, or other devices. If the moon were completely full, you’d look at it, but would have to squint to look at it closely, and even then might have to look away after a brief period.
When is the best time to view the moon this month?
The best time to view the moon this month will be Wednesday, January 24, which is the First Quarter moon. If you won’t have access to the sky this coming Wednesday, you can still get a very good view of the moon a few days before and a few days after!