A few nights before I left Charlotte I was sitting in my room discussing the moon with my sister. I was telling her that someone had mentioned to me that the moon would be upside down in Peru. I hadn’t stopped at that time to process the comment, but only a few nights before my departure, the moon quandary was more appealing than packing. I didn’t really have a problem understanding that my line of sight to the moon would be different here in Peru, but I had just never thought about it deeply and wasn’t sure what it would mean when I looked up at the moon.

Backing up a few years, I remember doing a lab in college that was designed for middle schoolers. It was done in a science teaching methods course, so it was intended to show me, as a education major, how I could teach science in a way that would engage my students at a deeper level. The initial assignment seemed easy enough: Go outside, find the moon, and use a protractor with a string tied to it to measure the angle of my line of sight to the moon. I was supposed to remember the spot and the time at which I made the measurement and do it again every night for a week. Easy enough, right?

That night I wandered outside to start the lab and the sky was clear, but I couldn’t find the moon. I thought it was strange, but I reminded myself that the moon wasn’t always out at all hours of the night. I will try earlier tomorrow, I told myself. When I couldn’t find it the second night at a different time, I resorted to looking up the rising and setting times on the Farmer’s Almanac. I probably should have deduced the answer sooner, but I was so certain I should be taking these measurements at night (since I was measuring the moon, after all). It seemed, however, that my professors had chosen to start this lab at a time when the moon was rising and setting during the daylight hours. What a rotten (and brilliant) trick! Finally I was able to measure the location of the moon and went on to understand the rising and setting times at a much deeper level. This middle school science lab, with its surprising twist, apparently made an impact on college Robbye.

Another portion of the same unit was on the phases of the moon, (which are different and unrelated to the rising and setting times, BTW). There is a common misconception that the phases of the moon are caused by the shadow of the earth. I think I knew that it wasn’t the shadow of the Earth (that’s an eclipse), but as a senior in college I still couldn’t explain the phases of the moon. I don’t like being in the dark (pun intended), so I loved what they showed me next. Here’s how you can learn a bit about the phases of the moon and prove to yourself that the phases are not related to the shadow of the earth on the moon:

  1. Put a Styrofoam ball on a popsicle stick.
  2. Go into a dark room with only one lamp as a light source.
  3. Stand facing the light source and hold the Styrofoam ball in front of you, but above your head.
  4. If your head is Earth and the Styrofoam ball is the moon, note that there is no light shining on the side of the moon that you can see from Earth. Thus, you are seeing a New Moon (or not seeing a New Moon, as it were, since the side you are seeing is not reflecting any light).
  5. Turn ever-so-slightly to your left (counter clockwise) keeping your arms up and out at the same angle they were. Note that light begins appearing on the right side of the moon (the right side of the part of the moon that you see from Earth) in the shape of a backward C.
  6. Continue turning until you are 90-degrees from your starting point. Note that you are seeing the moon slowly “fill-up” from the right side toward the left side. This is the waxing (filling up) phase of the moon.
  7. As you continue turning so that your back is toward the light source, you will see that the moon is now full. Are you still with me?
  8. Continue turning in the same direction and the moon begins to wane (or un-fill) from the right to the left. Is any of this looking familiar? And none of it had to do with your head (the Earth) making a shadow on the ball (moon), right?

This is roughly what the moon phases look like from North Carolina:

Nov 2011 Moon Calendar

Image taken from: http://stardate.org/nightsky/moon

I’d love to know if anyone tried this and, if so, if you learned anything new. I still remember this day quite distinctly because it was such an “ah-ha” moment for me both with the moon and with teaching styles. It has caused me to think about this lab and the phases of the moon every time I see the moon on a clear night! I can’t help but ask myself, “Is it waxing or waning?” and I imagine my Styrofoam ball on a stick. Isn’t it amazing how much we learn when our notion of the world is suddenly challenged? That’s why these labs were such good teaching methods for middle schoolers – they instantly challenged a wrong belief and then proceeded to guide the learner toward the correct understanding of the topic.

Now, back to my conversation with my sister about the upside-down moon. I knew about the orbit of the moon (the rising and setting), I knew about the phases, but I’d never considered that the moon might look different in the Southern Hemisphere. But how could it not be? The stars are different, right? It makes sense, but what would it look like?

A quick Google search brought me to a nice moon calendar that shows the user the phases of the moon by location on Earth: http://www.kwathabeng.co.za/travel/moon/moon-phase-calendar.html?country=Peru

This site is slightly incomplete, however. If you play with it a bit you will discover that it assumes that those in the Northern Hemisphere see the moon “fill-up” from right to left while those in the Southern Hemisphere see the moon “fill-up” from left to right. In reality, it’s a slow transition between the two. It’s true that if you live in the Northern Hemisphere about halfway between the Equator and the North Pole, then just after a New Moon you will see a crescent that looks like a backward C (see Nov 26-27 in the moon calendar image above). If you live in the Southern Hemisphere about halfway between the Equator and the South Pole, then just after a New Moon you will see a crescent that looks like a C that is not backward. [For the super nerds out there, I realize that this isn’t perfectly accurate since the earth is tilted slightly, but I’m going for generalizations here]. However, what if you’re decently close to the equator, like in Lima, Peru? The moon doesn’t suddenly flip over, but… but…

As I was walking home from the bus stop tonight, I was gazing at a moon that was filling from top to bottom. Yep, that’s right. It was a little over halfway full tonight, but the perfectly round side was on the top and the slightly bulging part was at the bottom. It looked something like this:

Moon with waxing side down

My view of the moon tonight

I’m not a scientist and I’m certainly not claiming to be terribly well versed in astronomy. Thus, my explanations of the phases of the moon are likely a bit lacking. What I do know, though, is that based on what I saw tonight, the moon is sideways in Peru. No, no… that’s not quite right, is it? That statement assumes that how I saw the moon in North Carolina is right and that everything else is relative to that. No, the moon looks different here. It waxes from top to bottom. It’s not right, it’s not sideways, it’s not wrong. It’s different, and I was a little surprised by this at first, but it’s pretty cool too.

Everything is different here in Peru. Even the things that are “the same” are different. Printer paper is A4 instead of 8.5×11, but I still have a printer/scanner sitting on my desk. The electricity is 220V/50Hz instead of 110V/60Hz, but I’m still typing on a computer and using a lamp as I write this. Even familiar things have an element of the unfamiliar. Each time my definition of the world is challenged, I have an incredible opportunity to learn, just like I did from the moon labs in college. Staring at the moon tonight I was reminded that it doesn’t surprise God that the moon is filling from top to bottom here, even if it is initially a surprise to me. The God who is teaching me what He has for my life is the same God who set the sun, moon, stars, and Earth into motion and nothing surprises Him. I know that I will continue to encounter new, surprising, frustrating, and fascinating things on this journey in Peru. I also know whom I can look to when I am feeling more overwhelmed than enthralled by these encounters, for none of this is a surprise to Him.