he night seems a bit darker today, as the Moon cannot be seen against the backdrop of stars. As Professor Turing enters, he places two Astronomy books on the table. The book on top is about the A.M.E. Quotient, and the cover shows a picture of a woman in a hijab giving an Astronomy presentation.

Hello everyone, and welcome back to Astronomy class. I have noticed an improvement in everyone's telescope techniques, which is excellent!

Just a few housekeeping announcements first. After the lecture next week, there will be a midterm. The midterm covers all material from the first five lessons. It is manageable for those who study, but it will be challenging for those who do not. Midterms are never timed, but you will want to finish them in a reasonable amount of time – I do not mind spending the whole night proctoring the Astronomy exams, but I am sure that a good number of you will want to go to bed at a reasonable hour.

Let’s begin our lesson!

The Moon Revisited

Today’s View of the Moon
Image Source: Flickr

If you look outside, the Moon is not there. Where is it? Oh yes, I have seen many hands go up, which means many of you have remembered. Yes, the moon is in the waning crescent phase, which means that the moon is not visible at this time of day. When could you have seen the Moon? If it were not cloudy, you could have seen the Moon earlier today. Good job. I can tell that you have been paying attention and studying. If we are not sure what phase the Moon is in today and had no access to lunar calendars, what magical device could we have used? Yes, that is correct – the Lunascope.

Here is another question. Which of these pictures looks more like your view the Moon? Notice that I have covered up the lunar calendars in the room – since you've seen the Moon several times in the last few weeks, your gut answer is probably correct. How many say that the left image is more representative of what you see? The right image?

   
Left: Image of the Far Side of the Moon
Right: Image of the Near Side of the Moon
Source: NASA

Good job! Yes, you are all correct – the right image of the Moon is more representative of what you see. The right image is an image of the “near” side of the Moon, and the left image is of the “far” side of the Moon. Interestingly, the near side of the Moon is the side that always faces Earth. No matter what phase the Moon is in, the near side of the Moon is always facing Earth – even though you cannot see a good portion of the Moon due to its phase. Two phrases that describe this situation are “tidal locking” and “synchronous rotation”. Either phrase can be used in this class, and I will use both phrases interchangeably as both are used regularly in magical Astronomical literature. In a future year, I will explain how gravity causes tidal locking. What you need to know for this class, however, is that tidal locking plays a major role in the Moon's magical effects on the Earth.

How is the near side of the Moon different from the far side of the Moon? From this picture, it is easy to see that the near side looks very different from the far side. In particular, the near side shows a very unique and complex relationship between light and dark designs. It makes the Moon very identifiable. In fact, if someone had shown the picture of the near side to you in the corridor last week, many of you would correctly guess that is the Moon. The far side, to many, may seem like just another moon or planet.

The difference between the light and dark sections is critical to understanding how lunar magic works. The Moon does not have a flat surface. Like the Earth, the Moon has places of high elevation and places of low elevation, as well as flat land and areas with more jagged profiles. Light portions of the Moon's surface represent areas of higher elevation – also known as the “highlands” - and dark portions of the Moon's surface represent flat, plain-like areas created by cooled lava from ancient volcanoes. These dark, flat areas are called “mare” or “seas” - based on a previous but incorrect assumption that these areas are lunar seas.

Remember how I mentioned earlier that moonlight was actually reflected sunlight? The Moon does not generate any light itself; all the light that you see coming from the Moon is actually reflected from the Sun. Some of the moonlight was originally earthlight, or light from the Sun that is reflected by the Earth. Either way, all moonlight was originally sunlight. Of course, the highlands reflect more light than the mare because the highlands are much lighter than the mare. That being said, we as Magical people know instinctively that moonlight does not have the same effects as sunlight – as we can see for example,  in werewolves. Werewolves maintain their human forms during the day and most nights. In their human forms, very few will realize that these people are werewolves. However, on the day of the full Moon, they turn into their wolf-like beast forms, and they will act with the violence and attitudes you would expect of giant wolves. These observations seem to suggest that even though the moonlight is reflected sunlight, something about being reflected from the Moon changes the light's magical properties.

A.M.E. - The Astronomy Magical Effect Quotient

The term A.M.E. Quotient, or Astronomy-based Magical Effect Quotient, describes the amount of magical effect a non-light-producing astronomical body has on another planet (or other object, such as a moon or even a spacecraft). Unless the other planet is specified, the default planet is Earth. The concept of the A.M.E. Quotient was first proposed and developed by Dr. Ayesha S. Mansour, whom you will learn about in the last lesson of this year. She was one of the hometown heroes of Stamford, Connecticut's magical community; she had moved to the United States from England when she was 3 and spent most of her life in Stamford, Connecticut. She was also a “foremother” in my academic family tree - in other words, she mentored my mentors. She loved making up fun-sounding new terms for her many discoveries; the original name for the A.M.E. Quotient was the “Astromeff Quotient”, but she changed it after realizing that other astronomers did not appreciate her sense of humor. Fun fact – she was an alumna of Hufflepuff house. Her mother, an Englishwoman, was the Hufflepuff Head Girl during her school days.

The equation for the A.M.E. Quotient is rather complex. However, I am not going to have you memorize the equation. All you need to know is the variables that constitute it. These factors are:

• Composition – what the astronomical object is made of
• Observed Size – how big the astronomical object seems from Earth
• Albedo – how much light and magic the astronomical object reflects off its surface
• Teamwork – how the astronomical object interacts with other astronomical objects
• Surface – type and character of the astronomical object's surface

These factors, which Mansour cleverly arranged into the acronym “C.O.A.T.S”, will be defined in next week's lesson. For today, all you need to know is that objects that appear large from Earth and objects that have a high albedo value (that reflect a lot of light) tend to have a very strong effect on the Earth. In addition, the composition and the surface of the astronomical object can change the type and quality of the magic that impacts the Earth. Generally, astronomical objects that have a large magical effect on the Earth, such as the Moon, have a high A.M.E. Quotient. Objects like undiscovered planets in star systems in other galaxies tend to have low A.M.E. Quotients because we rarely feel the affects of these planets on the Earth.

The A.M.E. Quotient is also why we learn so much about the surface and composition of planets in the Solar System in wizarding Astronomy classes. Yes, that information is fascinating, but that information can also help you make appropriate choices should you wish to take advantage of the planets' magic.

Class is dismissed. Thank you for coming to class today. Feel free to stay to ask questions before the midterm should you choose to do so!