1. Why Study Astronomy?

Astronomy is an exciting discipline for witches and wizards to pursue in their magical career. Many other studies you will undertake as students will involve utilising your own magical talent in a very direct way, as with intensive wandwork in Charms and Transfiguration, or manipulating and experimenting with magical animals, vegetables, and minerals in Care of Magical Creatures, Herbology, and Potions. Alas, one cannot move celestial bodies around the sky at will, nor can one transfigure the Moon into cheese to test how this would affect the colour of the Moondew flower, although this is not for want of trying. Instead, any magic you will use in this study will serve to augment your efforts to manipulate and enhance tools, and to improve your accuracy when taking measurements.

For the most part, however, the study of Astronomy can be pursued without the use of magic. This means however dismal your magical aptitude may be, you still can appreciate the wonders in the sky at any age, and anywhere in the world, without necessarily breaking any Wizarding Secrecy Laws. Astronomy is a wonderful study, therefore, because Muggles can participate alongside wizard astronomers, and share their findings without causing an international incident. And indeed, unlike many other magical pursuits that are beyond the scope of Muggle understanding (as well as there being many Muggle disciplines that elude even the brightest witches and wizards), the basics of Astronomy can be understood and enjoyed by everyone.

1a. What Is Astronomy?

At this point, you may be asking exactly what Astronomy is, because so far, we have discussed it rather nebulously. This is not a silly question to ask, as there is a lot of confusion in the wider public over the nature of Astronomy. First, a note to all the Muggle-raised students: the study of Astronomy in the wizarding world has some significant differences from Muggle Astronomy. Any education you have received in Astronomy previously still may be relevant, however, so do not be too dismayed. But even the most qualified Muggle astronomers would not be able to complete beginners' wizarding Astronomy courses without studying the material. You have been warned.

Astronomy, at its most basic, is the study of celestial objects - objects in the sky outside our Earth's atmosphere. You undoubtedly are familiar with many of these, such as the Sun, Moon, stars, and planets. Others, like nebulae, neutron stars, black holes, and galaxies, may be new to you, but all of these fall within the purview of the astronomer. The earliest civilisations did not have explanations at their disposal, and so described the heavens above as gods moving across the sky; told tales of hunters, wizards, bears, and dragons drawn by the stars; and saw foreboding or good fortune in comets and supernovae. Attempting to predict the movement of the Sun and Moon across the sky, calculating when eclipses would occur, understanding the strange paths of the planets over time - these were the first problems the earliest astronomers had to understand and explain. By learning how these bodies move, it is hoped you will be able to predict their movements yourself.

Nowadays, we can follow the movement of the planets spectacularly well, and our attention has moved toward what is occurring on these bodies. We consider questions such as how solar flares happen on the Sun, why Saturn has beautiful rings, and how all these different stars and galaxies were formed in the first place. Observing and understanding the processes behind events on distant bodies is very important to understanding the Universe around us and how it developed. Knowing the elements that constitute and formed the planets and stars helps us understand our own planet and its evolution.

1b. Astronomy's Relationship to Magic

Wizarding astronomers (from now on referred to simply as ‘astronomers’; we will make the distinction for the Muggle discipline only) observe the movement and activity of astronomical objects not just to understand the objects themselves, but to relate this information to magic undertaken by witches and wizards on Earth, observing how natural, celestial magic affects magic here. Harnessing the power of nature to create new spells or enhance potions has been going on since the first wizarding communities were established, but writing down the rules and predicting future celestial events is now undertaken by astronomers.

To illustrate, the Moon has many effects on Earth, even outside of magic. The Moon (in tandem with the Sun) causes the waters on Earth to ebb and flow (the tides), which in turn affects the behaviour of shoreline animals. For instance, certain species of coral will only release spores to reproduce in conjunction with the Full Moon, all in synchronicity. It is, therefore, not a great leap of logic to ask whether similar effects happen with magical flora and fauna, and even with the power of magic itself. In fact, it is surprisingly common for nearby celestial objects to have an effect on magic. For example, the potency of fluxweed reaches its useable peak at the Full Moon, and the invisibility potion is strengthened if bathed in moonlight. Lycanthropy, or the werewolf curse, will only manifest itself around the Full Moon, with the sufferer remaining

perfectly healthy at other times of the month. The effects of celestial bodies on magic will be discussed at length in this course, so that you may take advantage of these effects when perfecting your own spells and potions.

1c. What Astronomy Is Not!

What Astronomy is not, however, is Divination. Astrology is the study of how the movements of the planets affect our personalities and our personal fortunes, predicting the future in the process. Whilst both disciplines monitor the movement of celestial bodies to see their effects on Earth, astronomers only concern themselves with predicting the future as it relates to where these bodies will be tomorrow and beyond, and, to some extent, how they will change over time. In their earliest days, Astrology and Astronomy were considered one and the same. Whilst some Astrology may be referred to in the course (the signs of the Zodiac, for example), this will be primarily for historical context, and students will not be expected to divine the future beyond celestial mechanics.

In the Muggle world, the line between Astronomy and Astrology is very well-defined due to the lack of magic for celestial bodies to affect. Thus, astronomers may be offended when they are referred to as astrologers, and vice versa. You should appreciate this distinction before engageing in conversation with people of either of these professions, lest you receive a black eye, or at the least, a look of mild disdain and no invitation to their birthday party.

1d. Magical vs. Muggle Astronomy

Whilst you may find some concepts simple to grasp in this course (planets moving in orbits, the time it takes the Sun's light to reach us, etc.), developing those ideas was not a simple task. The Ancient Greek astronomers studied the heavens, yet even with all the credit we attribute to them in developing Western Civilisation, magical thinking, and Muggle ‘science,’ they still were unable, as a group, to come to the realisation that Earth was not at the centre of the Universe. It took until the 1500s for Nicolaus Copernicus to convince astronomers that Earth and the planets revolved around the Sun, a conclusion he drew from the burgeoning astronomical communities in both the Muggle and the wizarding world.

It may be tempting to think Muggle astronomers lag behind our wizarding fellows because of the advantages afforded by magic. However, the two communities have developed largely hand-in-hand. Wizards and witches had an advantage when it came to developing astronomical tools. For example, they could charm and transfigure materials to perfect the lens and the telescope much sooner than Muggles could develop techniques to get adequately smooth and curved lenses. Often, however, wizarding astronomers operated directly within the community of Muggle astronomers, making ‘discoveries’ (aided by undisclosed magic) of their own, and therefore advancing the Muggle ‘sciences.’ Thankfully, in the last hundred years or so, the Muggle astronomical community has advanced to the point that our intervention seldom is required to guide their research in the right direction.

The Muggle community has continued to push the boundaries and understanding of ‘physics’ (the study of the laws of the Universe), so much so that they have started the study of Cosmology, trying to answer the overarching question of how the Universe began in the first place. It is unfortunate to note, however, that the laws of the Universe the Muggles have developed through their study of physics may not hold true in the magical world; as ambitious as their goals may be, physics will never be complete without first taking into account magic. Consider one of the most fundamental physical laws applicable to astronomy - the law of gravity, which causes objects to attract and fall towards each other in some fashion. This fundamental physical law can be overcome with something as simple as the child's charm, Wingardium Leviosa. Muggle knowledge still has a long way to go before it is complete, but the extraordinary feats they have achieved so far without the use of magic are nothing to sniff at. Working together in groups of hundreds, even thousands if you include the people that have built and designed the equipment used, Muggles have put telescopes in space, seen starlight that is over twelve billion years old, and even helped put men onto the surface of the Moon. Some of the data is so precise and extensive, even our astronomers are scrambling to use it to test the extent of magic in the early days of the Universe.