1.1 What is Astronomy?

When you think of astronomy, one word should come into mind - SPACE! 

Astronomy is the scientific (or systematic) study of the universe.This definition of astronomy essentially covers three separate but interrelated components:

1. Celestial objects such as planets, stars, moons, comets, asteroids

2. Events that originate in space such as solar flares, supernova explosions, cosmic radiation

3. The corresponding physics, chemistry and evolution of these objects and events (in other words why do these celestial objects do what they do?)

Magical astronomy and Muggle astronomy are studied in very much the same way and as you will soon discover Magical astronomers rely on many of the discoveries that Muggle astronomers have made in the past. The crucial difference between the two disciplines is how this knowledge is used. Magical astronomers can use the information obtained by Muggle astronomers to find new ways to harness their magical energy and predict future events.

1.2 Introducing our Solar System

Earth is one of eight planets that form part of the Milky Way galaxy (therefore, WE must belong to the Milky Way galaxy). All eight planets orbit (or travel around) the Sun, they do this by travelling an elliptical path (which looks like a squashed circle) around the sun and back again. All eight planets travel at different speeds however they all spin in a counter-clockwise direction. 

The Solar System is comprised of two major components:

1. The Inner Solar System: which is made up of the planets Mercury, Venus Earth and Mars

2. The Outer Solar System: which is made up of the planets Jupiter, Saturn, Uranus and Neptune

These two components are separated by The Asteroid Belt. This is basically a large collection of Asteroids orbiting the sun in one big group - over 7,000 of them in fact! This acts as a physical barrier and is can be found orbiting the region between Mars and Jupiter.

Fig 1 Shows the order of the planets in our universe from the sun.

1.3 Introducing Stars

A star is a celestial body that generates light and other radiant energy and consists of a mass of gas held together by its own gravity in which the energy generated by nuclear reactions in the interior is balanced by the outflow of energy to the surface, and the inward-directed gravitational forces are balanced by the outward-directed gas and radiation pressures.

This definition is incredibly confusing so lets break it down into simpler terms (you won't need to know too much about stars until your second year of astronomy):

A star:

- Produce its own light.

- Consists of Hydrogen and Helium gas.

- Is held together by gravity.

- Generates energy by nuclear fusion (which occurs when atomic nuclei  "fuse" or join together to form a heavier nucleus). 

*The energy released from these nuclear fusion reactions allow us to see stars in the way that we do (bright and shiny).

Fig 2 Diagram showing nuclear fusion.

Stars have played numerous roles in both magical and muggle societies for centuries. In the earliest recorded days they were used for religious reasons as well as for navigation (making use of the fact that the North Star always pointed you North). Today, we can see them still being used in astrology and divination as a method for telling the future. 

Certain groups of stars have been seen to form recognisable patterns. These patterns are called constellations and are usually named after the form they take or identified with a mythological figure. In 1929 the International Astronomical Union officially recognised 88 constellations. There are twelve special constellations which make up the Zodiac. These specific constellations were selected because they all line along the equator. They have been attributed to deciding on one's future and play a big part in astrology and other divination techniques. (They cannot be used in this way while studying astronomy).  The twelve Zodiac Signs are Aries, Aquarius, Cancer, Capricorn, Gemini, Leo, Libra, Pisces, Sagittarius, Scorpio (Scorpius), Taurus, and Virgo.

Fig 3 The Twelve Zodiac Signs

More to be added shortly