Introduction From the first astronomy class that I have taken - the general astronomy class for students of all majors - to the last class I have taken for my master’s degree, so much has changed in terms of our knowledge of the universe. For example, one of my Muggle astronomer friends told me that now that New Horizons, one of NASA’s space probes, has provided Muggles with high-resolution images of Pluto, his newly published astronomy textbook is now out of date. Both Magical and Muggle astronomy are fields in which new discoveries are made every week. Orrery, the premier academic journal for cutting-edge research in Wizarding astronomy, is publishing weekly issues full of new astronomical discoveries. Let’s talk about the field itself. Astronomers define “astronomy” as the study of the universe. Both Muggles and Magical People consider topics such as observing celestial bodies (moons, planets, stars, and the like) in outer space, theorizing about how objects in outer space have been formed, and deducing the chemical makeup of these outer space objects as part of astronomy. However, while Magical and Muggle astronomy are related subjects, they do not completely overlap. Some may think that Muggle astronomy is identical to Magical astronomy, but without the Magical knowledge. However, the differences between the two are more subtle than that. For example, astrology - the study of how the happenings in outer space magically influence the happenings of people on Earth - is a major subfield of Magical astronomy. However, calling a Muggle astronomer’s field of study “astrology” will quickly result in one very angry Muggle.  In addition, astronomy is a field in which Muggles have certain advantages. For example, Muggles are excellent at observational and theoretical astronomy. Observational astronomy focuses on finding objects in space, whether it’s by visual observation or by “seeing” the object through analyzing data collected from space. Theoretical astronomy focuses on applying Muggle technology and Muggle astronomy concepts to a model in order to answer a question about the universe. In the field of astronomy, Muggles tend to make most of the observational discoveries and propose most of the theoretical concepts. Magical astronomers often subscribe to Muggle astronomy publications or attend Muggle astronomy institutions to get cutting-edge knowledge of observational and theoretical astronomy. That being said, Magical astronomers excel at applied astronomy. Many Muggles do not see astronomy as relevant to their lives other than as pretty decorations in the sky. They marvel at lunar eclipses, take pictures of the sunrise, and count the shooting stars dashing across an inky black background with their best friends. The more committed amateur Muggle astronomers may point their own telescope at the night sky and seek out known astronomical objects - or find some on their own. In contrast, Magical People are often concerned about - and knowledgeable about - the affairs of outer space because they directly affect magical life on Earth. Magical people know that, for example, the arrangement of the stars can predict the future and that the exposure of Basilisk eggs to moonlight could result in the early arrival of a deadly serpent. In fact, Magical astronomy is called “The Central Discipline” because of its application to every other magical subject. In other words, Magical astronomy connects all magical fields of study. Astronomy is truly a subject that connects many magical fields of study. The walls that separate disciplines from each other are restrictive, and the more that we can break them down, the more we can appreciate Magical learning as a whole. Magical astronomy will help you not only learn more about the magic that affects you in everyday life, but it will also help you to think in a more interdisciplinary way. No matter what your thoughts on Muggle astronomy, I encourage you to join me in learning about the magic beyond the Earth’s atmosphere. I will not disappoint.   Year 1 Preview This year, we will be learning about magical telescopes as well as the different properties that affect how much magic the Moon and other astronomical objects reflect back to the Earth. We will also be looking at the Moon’s phases with our telescopes, and we will be discussing other planets and their properties. Overall, it will be a fun class, and I am so glad that you will be joining me this term.

Magical Telescope Safety Now let’s talk about magical telescope safety. Your telescope is a fine magical instrument, and you should treat it with respect. This means no play fighting with them, no flinging them across the room, and no leaving them outside in the elements. Of course, common sense also applies here. For example, do not use a telescope in dangerous environments. While it is common to stay still while observing the skies, if you should have to take a step in either direction, pay attention to where you are walking. In fact, the glass lenses on the telescope are extremely fragile. There are scratch-resistant and break-resistant charms on them - however, you should still keep the lens caps on just in case. In order to ensure that you do not lose your lens caps, each telescope has the lens caps tied on to the sides of the telescope with a string, and each string is attached to the side of the telescope with a Sticking Charm. On the outside of the larger lens cap, there is a place to write your name - feel free to do so now if you have not done it yet. This will ensure that your telescope will be returned to you if it were to get lost. Broken lens glass may feel like Muggle broken glass, but broken Muggle glass is still dangerous. If you do have a lens glass break on you in class, call me, and I will take care of it. Usually I can fix your lenses with a spell. You should note that there are two astronomical items that you must not look at with your magical telescope. The most dangerous item to look at with your telescope is the brightest object in the sky - the Sun. Looking directly at the Sun with the naked eye - in other words, seeing the sun without using the help of another instrument to “zoom in” on the Sun - could result in irreversible damage to your eyes. Looking at the Sun with a telescope will also damage your eyes as well as the magical functions of your telescope.  In other words, the telescope will function like a Muggle telescope if you point it at the Sun. Solar eclipses are even more dangerous for your eyes and for your telescopes. Keeping the lens caps on the telescope will prevent the telescope from reaching this fate. The other time that you must not look at directly through a magical telescope is the Moon during a full Moon. Of course, unlike the Sun, the Moon can be safely seen with the naked eye. However, the light from a full Moon contains so much magical energy that, if light from the full Moon manages to enter directly into the telescope, it will not only destroy the magical properties of a magical telescope, but it will also physically crack the glass lenses of the telescope. Remember that a full Moon is powerful enough to transform werewolves. In order to prevent the light of the full Moon from entering the telescope, please use a lens cap when carrying around your instrument. We will discuss why this is the case in a future lesson. How can you figure out the phases of the Moon so you do not accidentally use the telescope on a full Moon? You can, of course, look outside yourself. If you would like to know the phase of the Moon on a future date - say, for a stargazing party - you could use a Moon chart or a Lunascope. A Moon chart is just what it sounds like. While these are handy to predict the phases of the Moon, they have a steep learning curve. Lunascopes, on the other hand, are easier to use but much more expensive. We will have more experience learning how to use these items in future years of this class. Today, we will be looking at the Moon. Take your telescopes, grab a quill and parchment, and come with me to the viewing areas of the Astronomy Tower.   Lunar Viewing When it comes to looking at the objects in the night sky, many budding Astronomers - Magical and Muggle - love to view the Moon. So much can be seen even without a telescope, and even more of the details can be seen with a telescope. Today, the Moon is in a waxing gibbous phase. One interesting thing to note is that while the Moon appears to be lit, it does not produce light on its own. The light that you see coming from the Moon is actually reflected from the Sun. More discussion about the magical properties of moonlight will be covered next lesson. Most of you have seen, at least from observation, that the Moon comes in different phases. In the new Moon phase, the Moon is not visible to us on Earth. Gradually, a sliver of Moon starts to appear - this is the waxing crescent phase. When half the moon is visible, the phase is called “first quarter” because it is the beginning fourth of the 30-day lunar cycle. The Moon then goes through a waxing gibbous phase until it becomes a full Moon on the fourteenth day of the cycle, and then the Moon’s visible area starts to shrink - waning gibbous, last quarter, waning crescent, then new Moon. Here are some hints for observing the Moon. The word “waxing” means growing, and the word “waning” means shrinking. Here in the United Kingdom, as well as anywhere in the Northern Hemisphere, if the right part of the Moon is lit, the Moon is waxing, and the visible part of the Moon will be growing in size in the next day. If the left part of the Moon is lit, the Moon is waning, and the visible part of the Moon will be smaller in size the next night. Observing the Moon by naked eye and by telescope in the gibbous phases - as well as by naked eye during the full Moon - is ideal. You can see the many details on the moon during the gibbous and full Moon phases. In addition, the Moon rises and sets at different times according to the Moon’s phase, and gibbous and full Moons tend to be visible deep into the night - which means that many of the Moon’s fine details are visible and not washed out by sunlight. Now, let’s quickly go over how to use our magical telescopes. Today, we will be learning how to use the magnification function of the telescope. First, remove the lens caps from the telescope and point it at the Moon. Turn the large metal knob on the left side of your telescope to zoom in so that the Moon fills up almost all of your field of vision. Zoom in slowly with the small metal knob on the same side. As you zoom in, notice how the telescope uses magic to focus your lenses. The charms in the telescope are able to focus your lenses for you, similar to an autofocus lens on a Muggle camera. Should you need to change to focus of the lens manually, pull out the smaller zoom knob and twist to adjust. Push the knob back into the telescope to turn on the magical focus. There you have it - the Moon in all its glory, through both a telescope lens and with the naked eye. Practice observing the Moon with the naked eye and through the telescope, and remember to not use the telescope during the full Moon.

Magical Telescope Tips and Tricks   Now that we have gone over the basics of how to use magical telescopes, let’s discuss some tips and tricks for magical telescope usage. As for telescope skills, do not be worried if you are not an expert right away - the more you practice, the better you will become. The first thing you will want to do before going outside is make sure that what you want to view will be visible. Of course, if you just want to have fun, you can just go outside and see what you can see, but if you are looking for something in particular, you will want to consult a table or other chart that can predict what can be seen at that particular time. Also, check the weather, as clouds and rain tend to obscure astronomical objects in the night sky. For your convenience, I have hung a lunar phase chart on the wall of this classroom, on the door to my office, and on the main entrance of the Astronomy Tower. This lunar phase chart is made by the finest magical astronomers in Mexico, and it contains many magical features that we will go over in a future lesson. Even without activating the magical aspects of the chart, one can see the predicted phases of the Moon for each particular day - from January on the left to December on the right. As you can see from the chart, last week there was a waxing gibbous Moon. The full Moon occurred earlier this week, and right now there is a waning gibbous Moon. In just over a few days, in what phase will the Moon be? That is right, the last quarter. Next week, in what phase will the Moon be? Yes, it will be a waning crescent. Good job, everyone! Your skill at reading this chart is improving already! Remember when I mentioned last lesson that the Moon’s visibility depends on its phase? Waning crescent Moons are best seen in daylight hours, and they tend to set before night. Therefore, do not be surprised if you do not see a crescent Moon in the sky next week. Not to worry - there are still plenty of items in the sky to look at, including the moons of other planets. The second thing you will want to do is ensure that your eyes and your telescope are adjusted to the night. Astronomy is super exciting, and I understand the urge to run outside and look at the skies as fast as possible. However, running from a warm, well-lit room in the castle to a cooler, darker environment outside means that your eyes and telescope need time to adjust. And please, for your telescope and your safety, please do not run outside - the night’s darkness and one’s excitement tends to blind one to unintentional traps along the way - and keep your telescope in the storage bag until you get to the viewing site. The bag is charmed with spells to greatly reduce the chance of your telescope breaking should you accidentally drop it on the ground. Once you are outside and at your intended viewing location, uncap your telescope and leave it exposed to the air but by your side for about ten minutes; this will give your telescope’s magical functions enough time to adjust to to the outside temperature. You can use the time to scan the area for good places to view the skies and/or for potential safety hazards and ambushes. One way to be safer and to have company is to bring along an astronomy partner to your observation sessions. When you are outside, do not bring a light or light-producing object, though you may carry the small magical Astronomer’s Lamp that comes with the telescope; this miniature light will illuminate your surroundings so that you can find your way and record your observations while having almost no effect on you and your telescope’s ability to see in the dark. After your observation session, cap your magical telescope on both ends and transport it back to the building in the enclosed bag. Once you are back in the building, quickly look over the telescope lenses for dust, dirt, and damage. Your lenses have been charmed to be resistant to dirt and damage, but it does not hurt to check to make sure. Should there be dirt that does not come off, come see me for some charmed telescope cleaning wipes. Be aware that it may take a few minutes for your eyes and your telescope to adjust again to the light levels and temperature indoors. Following these tips will help you get the most out of every telescope session. The more you practice these tips, the more positive habits you will develop, and the more automatic these will be. Try these tips out the next time you observe the night skies.     Advantages and Limits of Using a Magical Telescope Another common question that I encounter is “Why are we using magical telescopes when we could be using Muggle ones?“ Those with Muggle Astronomy backgrounds may know from personal experience or literature about some of the capabilities of Muggle telescopes built for amateurs. While Muggle telescopes for amateur Astronomers are amazing in their own right - many Astronomical discoveries have been and still are made by amateur Muggles - Magical telescopes have many advantages over Muggle telescopes. The first advantage a magical telescope has over a Muggle telescope is a more stable view, even without a tripod. Beginner-level Muggle telescopes are too large to put in your pocket and require a tripod to ensure that the shake that comes naturally when you hold a telescope, especially for a longer time,  does not affect your viewing experience. After all, no matter how still we stand, we cannot stop ourselves from shaking a bit, and the magnification on a telescope accentuates the previously almost unnoticeable movement. On the other hand, the spells used in making a magical telescope not only ensure that they are smaller and lighter than their Muggle counterparts - after all, you can fit these magical telescopes in your pocket - but they also ensure that the view on the telescope compensates for the unmistakable “shake” that occurs when viewing objects at higher magnification. In addition, a magical telescope will give a better magnification factor than a Muggle telescope many times its size. There is no way that a Muggle telescope on a tripod can beat the magnification available on our handheld von Rheticus model student telescopes. Later this year, when we point our telescopes at other planets in the Solar System, we will see that our magical telescopes can give us very clear views of those planets. Many Muggle telescopes meant for amateurs cannot. Likewise, when using magical telescopes, there is much less loss of resolution than in Muggle telescopes at higher magnifications. At very high magnifications, many amateur Muggle telescopes have blurry images. The magical charms and methods used in the construction of magical telescopes ensure that even on the highest magnification, magical telescopes will give crisp images. If you attempt to go past the limits of your magical telescope's capabilities, the telescope will let you know - the whole viewing area will be given an unmistakable blue tint, and the bottom of the screen will suggest that you use a telescope with higher magnification. Perhaps the most interesting advantage of using a magical telescope are the magically-enhanced special features. Visual observation is only one of the many things a magical telescope can do. Next week, we will learn about one of the many special features available on this telescope. Of course, magical telescopes have their limits. As mentioned above, there is a limit to how much magnification a magical telescope can provide. In addition, magical telescopes – like Muggle telescopes – have a narrower field of vision in higher magnifications than in lower magnifications. That being said, magical telescopes have many advantages over Muggle telescopes, which is why I am teaching you how to use magical telescopes in class.

The Moon Revisited 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? 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.

A.M.E. Basics Review Last class, we talked about the Astronomy-based Magical Effect Quotient, or the A.M.E. When we ask about how much of an effect the Moon, for example, has on the Earth, we are discussing the Moon to Earth A.M.E. We also went over the five parts of the A.M.E. What were those again? Yes, that is correct. The five parts of the A.M.E. 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 Today, we will go over each part of the A.M.E. individually. In future years, we will go in depth into the physical properties of planets, moons, and other astronomical bodies, and the above details will be crucial to understanding how astronomical magic affects us. Remember, for these descriptions, we are assuming that we are standing on the Earth, but should you be lucky enough to be given the chance to leave the Earth’s atmosphere, you can apply the same concepts to your location at any place in the universe.   Composition Composition refers to the molecular makeup of an astronomical body. Both the surface composition as well as the internal geology of the planet or moon is important because both alter the type of the magical effect of reflected light. For example, there is much iron in Mars’ composition. In fact, Mars looks red to us on Earth because of the iron oxide on the planet’s surface. Because of the effect of the iron, magic being reflected by Mars tends to be reactive, chaotic, and high-energy - you will learn more about this in Alchemy next year. Mars’ iron content also affects its use in Divination, as the sighting of Mars can be linked to readings of war and battle. You can look forward to more information about Mars’ symbolic meaning in Divination next year, if you choose to take the class.   Observed Size This property is self-explanatory. Small objects can look bigger in the sky than larger objects because they are much nearer to us. For example, the Moon appears to be bigger than Mars in our sky even though the Moon is much smaller than Mars. How does this relate to magic? In general, non-light-producing objects that seem larger in appearance tend to have a stronger magical influence than those that have a smaller appearance. This is because objects that are closer tend to reflect more magic on the Earth than objects that are further away. In this example, the Moon has a stronger magical effect on the Earth than Mars does. While the effects of Mars can be powerful when used effectively, the magic reflected from the Moon has a significant impact on the Earth and is easy to harness.   Albedo Like light, magic is generated from the Sun and reflected off objects in space. Some objects reflect the magic better than others. The word that describes how much of the received magic a surface reflects is called magical albedo. A surface’s albedo can be expressed in any number between 0 and 1; a surface with a magical albedo value of 0, seen on the left side of the above image, reflects no magic at all, while a surface with a magical albedo of 1 reflects all the energy that shines at it. Magical albedo can be estimated by visual albedo - light surfaces tend to reflect more magical energy than dark surfaces. For example, the light surfaces of the Moon reflect more magic than the dark surfaces of the Moon. This is also why the magic during the full Moon is very strong; since so many of the light surfaces of the Moon are visible to Earth, we know that there is much magical energy sent to the Earth during a full Moon.   Teamwork (Interference) When magic is reflected off of astronomical objects, it is influenced by the magic of other objects. Sometimes magical effects influence one another to create different magical effects. Dr. Mansour originally called this “teamwork”, but the word currently used today is “interference”. There are two types of interference. Constructive interference occurs when reflections from two or more magical sources enhance each other so that the magic’s effects are stronger. Destructive interference occurs when reflections from two or more magical sources partly or completely cancel each other out so that there is less or no magic. Complete constructive interference and complete destructive interference - the former refers to a situation with the maximum strengthening of the reflected magic, while the latter refers to essentially a complete cancellation of the reflected magic - are rare, as most interference interactions are complex. Teamwork is similar to the concept of transitionals. In transitionals, you will use the relationship between two objects in the solar system, such as Venus and Mars, to change the qualities of an element. You can learn more about transitionals next year in Alchemy. Teamwork is also similar to what one would see in astrology. When diviners use astrology, they study how stars, planets, and the like work together  to produce magical effects.   Surface The surface of an astronomical object has an effect on the type of magic that is transmitted to the Earth. For example, flat areas will have different effects than mountainous areas. This is why we will be learning about surface geology of planets, moons, and other features later on in our Astronomy program. For other objects with very varied magical effects, astronomers often study aspects such as a planet’s rotation, particularly if it is irregular. Let’s take the Moon as an example. Ever notice that the effect of the full Moon is rather uniform no matter when the full Moon occurs? This is because of the Moon’s synchronous rotation - even though the Moon looks different on the near and the far sides, the near side always faces the Earth, and therefore the same side of the Moon reflects the magic back to the Earth. As a result, magic reflected from the Moon is very predictable. This is why Moon-based magic is used relatively reliably  for many specific magical processes, such as maturing Veritaserum potions.   I will be ending class now so that you will have enough time to complete your midterms. I will be passing them out now; once you are done, you can hand them to me and head back to your dorms. There will also be additional homework distributed; please complete these for next class period. Good luck on the midterms!

Telescope Use: Measuring an Object’s Size Please look up at the Moon without your telescope. How big is the Moon in the sky? It is hard to measure the Moon’s apparent size with our naked eyes. Luckily, we have our magical telescopes to help us. While the telescopes that we are using in class are basic models, they have quite a few useful features. For example, you can use the telescope to measure the size of an object in the sky. Since the Moon is visible today, let’s measure the size of the Moon. First, point the telescope at the Moon and zoom in. Remember, the zoom controls are on the left side of the telescope - the large knob is for large adjustments, and the small knob is for smaller adjustments. Then, locate the button, which is labeled “S” for “size”. You can find it on the right side of the telescope. Then, push down the button. A ruler will appear in your view - estimate the size of the Moon based on the markings of the lens. Let’s point our telescopes at the Moon and take a look. One great thing about this ruler is that it it will zoom in and out as you zoom in and out of the Moon. Remember that the ruler that appears in your lens always measures the size of the Moon as if it were to be seen with a naked eye. For the best results, zoom in as close as you can. As you zoom in, the magical ruler that appears in the lens will show more detailed size increments. You can also see your current magnification level displayed on the upper right side. Zoom in and out slightly on the Moon and see what happens. Good job, everyone! Notice how much easier it is to use our magical telescopes than our naked eyes? More complex models of telescopes contain additional magical functions. For example, higher-end models will let you measure the size and other attributes of extraterrestrial objects by saying aloud the quality that you wish to measure. The words will trigger the appropriate charm in the telescope to show the appropriate scales on the screen. Let’s now discuss how to use your telescopes to measure an object’s albedo.   Telescope: Measuring an Object’s Albedo Measuring an object’s albedo is rather similar to measuring an object’s size. As I mentioned in a previous lesson, magical albedo is a measure of how much magic is reflected off the surface of an astronomical body - the lowest value possible is “0”, which refers to complete absorption of magic by the surface, and the highest possible value is “1”, which refers to a complete reflection of magic right back at us. All you have to do is push down on the button with the  “A” marking. When you do, the object that you are looking at will turn different shades of green depending on the albedo. In addition, a bar with 10 different shades of green will appear on the side. The shades of green are arranged from light to dark, with the darker shade standing for lower values and the lighter shade standing for higher values. For example, the darkest shade stands for readings of 0.0 to 0.1, the next darkest stands for 0.1 to 0.2, and so on. Let’s take a look at the Moon. Notice that the bright parts of the Moon have high albedo, while the dark parts of the Moon have low albedo. Also, notice how much of the magic that gets reflected back at the Earth comes from locations with high values. I am going around and checking on everyone in class - if you have a question, please let me know. Now, we will be going over our assignment for next week.   Viewing the Planets One challenge when teaching Astronomy is that the objects that we will be looking at may not be visible to us during our class period on Wednesday night. It turns out that the second half of November, for example, is great for viewing only a few planets. Three of them - Venus, Mars, and Jupiter - are visible right before dawn. Sometime before this class and next class, I would like you to go out and view these planets. I have given everyone temporary passes for permission to be out in the castle around dawn. Please bundle up as the temperatures around that time may be chilly for some, and feel free to bring a classmate or several to the viewing party. I will post this chart here in front of my office and by the southeast corner of the Tower so that you can be reminded of where to look. Finding the planets is very easy. First, locate the constellation Corvus - it should be in the southeast portion of the sky. Then find the star Spica, which should be left of the top two stars in the Corvus constellation. We will learn more about Spica in future years. The three planets should be aligned on the diagonal, with Venus being the lower planet, Mars being the middle planet, and Jupiter being the planet in the upper part of your view. I will be in the Astronomy tower on Wednesday and Friday morning at dawn. If you have trouble finding these planets, please come seek me out, and I will help you. Bring your friends and housemates if you would like. This is important, as next lesson we will be learning a little more about these planets and their moons.

Beyond the Earth and the Moon So far this year, we’ve focused mostly on the magical relationships between the Earth and the Moon. While the Moon is very important to magic on Earth, there are also many other Astronomical bodies present in our Solar System. There is, of course, our Sun - the producer of all magic in the Solar System. Practically all magic that is reflected off Solar System planets has originated from the Sun. Also, the Sun pulls all of the Solar System planets, as well as objects such as asteroid belts and some comets, into orbits, which allow us to utilize the magical relationships we use today. In fact, the term “Solar System” includes the Sun and everything that revolves around it, from the great planets to the smallest rocks in the Asteroid Belt. As for the planets in the Solar System, there are eight that are considered in the Magical world (and most of the Muggle world) to be planets. From closest to furthest from the sun, they are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. The four that are closest to the Sun are considered the Inner Planets, and they share similar features. Likewise, the last four are considered the Outer Planets, and they also share commonalities. There is also the dwarf planet Pluto. When the International Astronomical Union (IAU), one of the premier Muggle Astronomical associations, deemed that Pluto is not a planet in 2006, there was controversy, and there are some today who still consider Pluto to be a planet. Either way, Pluto is a part of the Solar System and thus has some effect on astronomical magic. In addition to the many planets of the Solar System, there are also many moons. The Earth is unique in the Solar System in that it has exactly one moon, and our Moon is also relatively large compared to the Earth. In fact, the Earth’s Moon is so large that it is able to totally eclipse the Sun during a solar eclipse. Among the Inner Planets, there are only three moons - Earth’s Moon, and Mars’ potato-shaped moons, Phobos and Deimos. In contrast, many of the Outer Planets have a whole collection of moons, and new moons are still being discovered. For example, Jupiter currently has the most known moons at the time of this lesson. Of Jupiter’s 67 known moons, four of the most famous - the Galilean moons - were used by Galileo Galilei as evidence for a Sun-centered Solar System. Even Pluto, perhaps the most famous planetoid in the Solar System, has five moons. While moons have similar features, they also have unique properties. For example, Europa, perhaps the most well-known of the Galilean moons in the wizarding world, is covered in ice. Furthermore, there are other features of the Solar System worth noting - asteroids belts, comets and the like. Then there is magic coming from outside of the Solar System - in particular, constellations for astrology. The whole universe contains objects that impact and emit magical energy, which makes Astronomy such an important and vital subject.   Inner Planets vs. Outer Planets The eight planets in the Solar System are, as mentioned above, split into the Inner Planets and the Outer Planets. The Inner Planets refer to Mercury, Venus, Earth, and Mars, while the Outer Planets refer to Jupiter, Saturn, Uranus, and Neptune. The image I have presented above shows the eight planets in the Solar System scaled according to size, with the Inner Planets in the front and the Outer Planets in the back. Perhaps the most obvious difference between the Inner Planets and the Outer Planets is this size difference - the Outer Planets are much larger than the Inner Planets. In fact, Earth is the largest of the Inner Planets even though it is quite small for a planet. That being said, the planets of Mercury, Venus, and Mars have much more of a magical effect on Earth than, say, Uranus or Neptune. This is because Mercury, Venus, and Mars have larger observed sizes since they are closer to the Earth, and thus the Inner Planets also have higher A.M.E.’s than Uranus or Neptune. Of all the Outer Planets, only Jupiter and Saturn were noticed by Astronomers before telescopes, and thus - due to their observed size and brightness - these planets have relatively noticeable A.M.E.’s and thus have a strong magical effect on the Earth. Two other differences between the Inner Planets and Outer Planets are surface and composition. The surfaces of the Inner Planets are rocky, and although planets such as Venus and Earth - the two largest of the Inner Planets - have thick atmospheres, any spacecraft that attempted to land on the planets would be able to land on solid ground. Thus, all four of the Inner Planets have surface features. You will find landscapes of volcanic origin as well as craters. If you go deeper into these planets, you will also find that these planets are made of many heavier elements such as metals, and the cores are very metallic. In contrast, the Outer Planets, while they are large, do not have hard surfaces. They are called “Gas Giants” because they are made of gas: a spacecraft that attempts to land on such a planet would not find a solid surface. Composition-wise, the Outer Planets are made of hydrogen and helium, the same components that make up our Sun. The Outer Planets also have ring systems and tend to have interesting moons.

Differences Among Inner Planets In the previous lesson, we learned about the Inner Planets and how they are similar to one another. For example, they are small in size, and they have few or no moons. They are also very rocky, and they have metallic cores. Their surfaces possess discernible texture because they do have a hard surface, and they have craters. While I did not mention this additional fact specifically, I showed images of the planets, and we all could see that the Inner Planets, though they are small, are spherical in shape. The Inner Planets, however, are not exactly the same. In terms of magic, the Inner Planets were associated with different - and sometimes conflicting - qualities. For example, Venus was associated with calmness, while Mars was associated with chaos. In Alchemy next year, you will learn about how the diametrically different properties of Venus and Mars can be used to change certain qualities of elements.  Here is the picture of just the Inner Planets again. In the top row, we have Earth on the left and Venus on the right. In the bottom row - Mars on the left, Mercury on the right. Size-wise, the planets are depicted to scale. As you can see, Mercury is the smallest of the Inner Planets. Venus and Earth are similar in size but look very different. Let us talk about Mercury, the closest planet to the Sun. As you can see from the picture, it is essentially a cratered ball of rock. In fact, with its mare-like sections and many craters, it may even look a little like our Moon. There is an atmosphere on Mercury, but it is very thin - too thin to burn up any space rocks that manage to get pulled towards the planet by its gravity. We will talk more about gravity in future years. Also, because the atmosphere is so thin, the planet has both very hot areas and very cold areas at the same time. That being said, this ball of rock is associated with the magic of speed and intuition. Perhaps it’s the 88-day year that gives it its association with speed, and perhaps it’s the planet’s varied temperatures and vulnerability to space rocks that give it its penchant for intuition. Venus and Earth are considered “sister planets” because they are roughly around the same size and adjacent to one another, Venus being the second planet from the Sun. Venus has cloud cover and an atmosphere thick enough to burn up many incoming meteorites. However, the planet is also very different from Earth. For example, Venus is covered by clouds made of sulfur dioxide, and the atmosphere of Venus is mostly carbon dioxide. This atmosphere makes Venus a very hot planet, as it traps in a lot of the heat. In Alchemical applications, Venus represents love and calm, even though there are many storms on the planet. Do the storms represent the hidden side of love, and does the atmosphere’s effect in burning up meteorites bring about a sense of calm? Magical astronomers are still debating.  Then, of course, follows Mars, our red neighbor on the other side. Of all the Inner Planets, it is furthest from the Sun. Mars also has a thin atmosphere, but thicker than Mercury’s. That being said, you can see Mars’ red surface from Earth, so the atmosphere must not be very thick. Even though Mars’ atmosphere is made mostly of carbon dioxide, it does little to stop meteorites from crashing into the surface. The surface is red because of the iron oxide in the Martian crust. Likewise, Mars is associated with chaos, youth, and masculinity. The red is said to symbolize blood and the reactive, violent qualities that come with the planet.    Differences Among the Outer Planets The Outer Planets, as well, hold their differences. This section will focus on the differences between Jupiter and Saturn, as these two planets have the most impact on the A.M.E. Jupiter and Saturn have many similarities - they are the largest and second largest planets in the Solar System, and they are both made of primarily hydrogen and helium. However, Jupiter is associated with the qualities of strength and guardianship, while Saturn is associated with wisdom.  Jupiter is known for its distinctive bands and its Great Red Spot, a storm so big that it is actually bigger than the size of the Earth! Inside these storms, the winds whirl at high speed, which seems interesting, especially since the planet itself has characteristics of strength. In fact, one can argue that Jupiter portrays strength in a very complex and unique manner - as it has the ability to remain emotionally intact even in a turbulent state of mind. Then, of course, there are Saturn’s rings, perhaps the planet’s most recognizable feature. Even though the rings appear to be solid, they are not: instead they are made of myriads of small pieces of ice and rock, not exactly the most exciting building blocks. That being said, the magic that originates from light being reflected from Saturn has the characteristic of wisdom. Perhaps’ Saturn’s ability to create beautiful rings out of broken pieces of rock and ice - rough and jagged - are an analogy of wisdom itself.   Comets Comets are essentially ice-covered rocks. The ice can be water ice, or it can be ice of other materials, such as frozen carbon dioxide or methane. These celestial objects come close to the Sun with varying frequency, and when they do approach, their magic becomes available for us to use. Luckily, a good number of Solar System comet paths have been charted, and thus we as astronomers have a good idea of when the next comet will come visit.  One example is Halley’s Comet, which is pictured at front of the class. Unlike the planets, which orbit in an almost-circular path around the Sun, this comet’s orbit is elliptical and crosses the orbits of the Outer Planets. However, approximately once every 75 years, you can see the the comet in the Earth’s skies, and it is one of the few comets that can be seen without a telescope. There is much power to be had by harnessing the magic from these comets. When Halley’s Comet last visited Earth’s neighborhood in 1986, there was plenty of excitement within the Magical astronomy community, and much Magical research relating to the comet was performed and published. Even Magical newspapers covered the arrival of the comet in great detail. We will learn more about the magic and influence of comets in future years.

Good evening, everyone, and thank you for coming to class today. As you know, today you will be taking the final exam. Before the exam, however, Professor Dumbledore and I will be discussing the lives of two of the astronomers mentioned in class this year. In the interest of time, I will have Professor Dumbledore talk first. Sometimes when discussing the amazing achievements of wizarding astronomers in the past, we lose sight of the personalities who are responsible for the magical astronomy discoveries and insights that we know today. We are thus privileged today to listen Professor Dumbledore’s first-hand experience in interacting with the famous Dr. Mansour. Please welcome Professor Dumbledore!   "Hello everyone! Professor Lunet asked me to come and further your knowledge on the ever so lovely Dr. Ayesha S. Mansour, whom you heard about in Lesson Four. She was a dear friend of my aunt, and I had the pleasure of getting to work with her one summer before finishing my education! She truly was a delightful lady… Does anyone remember what she did? If so, wonderful! If not, we will be discussing it again here, so don’t worry!  Dr. Mansour was born in England to an American father and an English mother on July 30, 1929. She spent most of her childhood in Stamford, but once she became of school age, her parents decided that they wanted her to attend Hogwarts School of Witchcraft and Wizardry, where her mother received her education. Her father was a Muggle, and her mother wanted first-hand knowledge of the education that her daughter would be getting. Thus they would travel between England and the United States, wanting her familiar with the United Kingdom before sending her off to school alone. When she was eleven, she was sent to Hogwarts, where she was sorted into Hufflepuff House. She had been nervous about her sorting, but was happy with the house that she now refers to as being her home away from home during her schooling. She always had an extremely bubbly and joking personality, something that made her well liked among other students. Dr. Mansour had never been a poor student, but to say that she was a star pupil was a small stretch. However, when she began Astronomy class, something clicked. She fell in love with the subject within the first few weeks of class and began studying independently with her professor. She constantly craved new knowledge about the subject, even in aspects that had not yet been discovered in either Wizard or Muggle Astronomy. She stayed with the subject all through her schooling, finishing with Outstanding marks each year, including her N.E.W.T.’s. This led her to go into Astronomy research as soon as she graduated Hogwarts, still desiring more knowledge on the subject! She worked with a group of other Wizard Astronomers for a few years before leaving to pursue her own research. She did so for nearly ten years before making her big discovery. Dr. Mansour is known within the Astronomy community for her discovery of A.M.E. From there, you know the rest of the story! Thank you for allowing me to visit within your classroom and I hope you have a wonderful rest of your lesson!"    Thank you, Professor Dumbledore. Let’s have a round of applause for him. As you can hear from Professor Dumbledore’s story, anyone can be an astronomer. Our stereotype of astronomers is a pensive, introverted male who loves to gaze into the starry sky. He seems to have a calm demeanor, but he is also very logical and soft-spoken. He would probably be a Ravenclaw if he had been a Hogwarts student. That is, of course, a stereotype. As you can see, Dr. Mansour did not fit the stereotype. She was bubbly and extroverted, and she had a great sense of humor. Many say that her enthusiasm was contagious, and she could fill a room with her excitement for Astronomy. While Dr. Mansour moved to the wizarding portion of Stamford after her graduation, she regularly enjoyed venturing to the Muggle portions of the city. In fact, she often mentioned that she got her best ideas walking down the Muggle streets and visiting Muggle cafes. The second person that we will be learning about today is George von Rheticus, a wizarding Astronomer. Here, I have a print of his portrait. Where may have you seen this portrait? Yes, this image is taken from one of the magical portraits in our school. Did you know that von Rheticus was the only student of Nicholas Copernicus, the famous Muggle Astronomer?  Let’s talk a little about von Rheticus’ mentor, Copernicus. Copernicus was a Muggle Astronomer who first argued that the Sun, not the Earth was the center of our solar system. For thousands of years, many people believed Ptolemy’s model of the universe - namely, that the Earth is at the center of the universe. Now, Ptolemy is an important person when it comes to Astronomy - after all, we do have a chocolate frog card named after him - but he was definitely wrong when it comes to his model of the Solar System . Only after many years of research and study was Copernicus able to propose an alternative - that the Earth revolved around the Sun, not vice versa. If it were not for von Rheticus’ work, Copernicus’ ideas may not have been published. Copernicus’ Sun-centric concepts were published in his most famous work, On the Revolutions of the Heavenly Spheres. Von Rheticus played a major role in the publishing of the book. Von Rheticus was also known for two other things - his love for (and work with) triangles, and his work in making astronomical instruments. While telescopes did not become very useful until a century later, von Rheticus made other Muggle and Magical astronomical instruments. He also did a large amount of work in trigonometry, which is a branch of mathematics that focuses on using triangles to solve problems. One interesting aspect about von Rheticus’ life is that his father was not only a wizard but a crook in the Muggle world. His name was originally George Iserin. Von Rheticus’ father was caught stealing, and as punishment, Rheticus’ father was not allowed to use the name Iserin anymore. As a consequence, von Rheticus used his mother’s maiden name and became George de Porris. Later, von Rheticus changed his name again. At that time in history, most intellectual works were still written in Latin, so many intellectual researchers changed their names to Latin names. This was when he became von Rheticus.  As for von Rheticus’ personality, we do not know for sure. Assuming that the portrait artist captured von Rheticus’ personality - and you will learn more about magical portraits in Magical Art - von Rheticus seemed to like helping others except those that he called “scoundrels”. Sometimes, to prove that you are good person, he will require you to answer an Astronomy question. Perhaps he developed this attitude due to his own personal relationship with his father, who was quite a scoundrel.   Thank you for being part of my class this term. This has been an amazing year, and I am so happy to have everyone in class. Next year, I will be talking about the Moon and it’s effect on the Earth. There will be lessons on eclipses, magical plants, Mooncalves, and much more. I am super excited to be teaching everyone here next year. I will be passing out the finals right now. After you complete them, you may leave the class. Good luck!