While reading Chapter 2 in the textbook, I realized how much of a difference living in the southern hemisphere would affect the way you view space. I think we generally tend to think of things as being similar if not the same in the southern hemisphere, especially something as universal as the stars in the sky or phases of the moon. However this is not the case, and although the textbook doesn’t mention explicitly the differences in moon phases, I did some extra research.
When I learned about the phases of the moon in elementary or middle school, I was taught to identify a waning crescent vs. a waxing crescent based on which side of the moon was lit. For a waxing crescent, the moon was lit on the right side and vice versa for a waning crescent; therefore, I always associated waxing with the right-direction. However, this logic actually only applies in the northern hemisphere. In the southern hemisphere, the moon appears “upside down,” but the name of the phase the moon is in remains the same no matter which hemisphere you are in. Thus, the moon is lit on the left side while waxing and the right side while waning. The part of the moon lit by the sun grows from right to left in the northern hemisphere and left to right in the southern hemisphere. This is a similar concept to stars appearing to rotate counterclockwise in the northern hemisphere and clockwise in the southern hemisphere. Like most things in astronomy, it is all a matter of perspective. As a result, to tell which phase the moon is in from a single picture, the first question you should ask is which hemisphere the photo was taken from. That being said, no matter which hemisphere you are in, if the moon appears to grow in size (perhaps over a series of pictures), it is waxing, and waning if shrinking. I use the mnemonic, “wax on, wane off” to remember.
The picture below shows the difference between hemispheres, and this website does a good job of explaining further.
