In honour of astronomy – this year being the International Year of Astronomy – I have decided to embark on an astronomic journey of astronomical proportions, of discovery and perhaps self-discovery, and overflowing with other ill-devised puns.
I shall be exploring the night sky each month of the year, documenting the observations in easy to read articles, with the hope of providing an easy-to-follow guide to the Maltese night sky, and perhaps induce a love for what is surely one of the most enjoyable and accessible hobbies in the world.
The monthly articles are aimed at Maltese people first and foremost, in order for them to be able to enjoy the visual splendour of the heavens and discover the mysteries of space, but can be of use to most people in the Northern Hemisphere.
Astronomy is one of the oldest practised hobbies in the world. The reason for this is fairly obvious: at its most basic form, astronomy can be practised with the most rudimentary tools available to us all, and its wonders can be enjoyed with the naked eye – all one needs to gaze at the stars is a clear sky and a dark location. Astronomy can be practised by anyone, anywhere on Earth. What better way to unite the people of the world than under the umbrella of the night sky?
2009 is the International Year of Astronomy – a year which marks the 400th anniversary since Galileo explored the heavens with one of the first astronomical telescopes. It is also the 40th anniversary of the Apollo mission that landed Man on the Moon. The IYA will be celebrated through various activities throughout the world, making it a truly global celebration of astronomy.Anyone can partake in this world-wide celebration, and I hope that this guide will be of help to anyone who wishes to join in this other-worldly adventure.
Each month we shall explore one constellation of the zodiac, as well as some other constellations and other interesting celestial objects. For astronomers the importance of the zodiac is minimal, but the zodiacal constellations do provide an easy reference point for marking the paths of the Moon and the planets. For instance, knowing that Jupiter is near Sagittarius can be helpful in spotting it and, especially for Maltese observers, in choosing an appropriate site to view it from.
No special equipment is necessary – your eyes and a modest pair of binoculars (7 x 30 or 10 x 50 ideally) will do. Telescopes reveal more detail, but binoculars are enough for the beginner, opening a world of wonders invisible to the unaided eye.
Note: The monthly guides are meant for everyone to enjoy and are therefore kept as simple as possible, highlighting only the brighter celestial objects. However there are many other things to explore if you’re hungry for more and up to the challenge. (See the links section below for some useful resources).
Sky Watching Tips:
- During winter in particular temperatures can drop considerably at night while observing in the open air, so make sure you wear warm clothing. Wearing layers can be advantageous since you can remove or add clothing as desired. I cannot emphasise enough the importance of wearing a beanie or some other head garment in winter – covering your head is essential in order to keep warm since this is where most of our body heat escapes from.
- It’s best to observe stars, clusters and other deep-sky objects on moonless nights (new moon) or when the moon is in its last quarter since it rises late at night, giving you a chance to explore the fainter objects of the heavens, which would otherwise be dimmed by the powerful light of the moon.
- Try to stay away as much as possible from any light sources – city lights, street lights, headlights – as these will prevent you from seeing the fainter objects in the sky.
Here are some links that you might find useful in your exploration of space:
http://stardate.org/ – contains various information and resources that beginners should find very useful, including a moon phase calendar.
http://www.skymaps.com/ – a very informative site where you can download monthly star charts with a map of the night sky and a list of the brighter and more interesting celestial objects that are visible in that particular month. Ideal for those who would like to venture deeper into space and unravel the mysteries of the night sky.
http://www.skyviewcafe.com/ – An online planetarium showing how the various constellations and other celestial objects will appear from your location at a given time. Indispensable for accurate pre-planning of an observation session.
Glossary:
Asteroid: An asteroid is a rocky celestial body orbiting the Sun. They are bigger than meteoroids and similar to, but smaller than planets. Hence they are sometimes called minor planets.
Asterism: An asterism is an easily recognized pattern of stars usually part of a bigger constellation. A well-known example is the Big Dipper asterism, which resembles a plough or dipper, and is part of the constellation Ursa Major. An asterism is not itself a constellation.
AU: An astronomical unit (AU) is a unit of measure approximately the distance between Earth and Sol.
Black Hole: A tiny region of space where gravity is so strong that not even light can manage to escape.
Binary Stars: A binary star is a star system comprising of two stars orbiting each other.
Cluster: A star cluster is a group of stars, which can range from a few hundred to several thousands or millions of stars. An open star cluster is a cluster of randomly scattered stars. They are not as densely populated as globular clusters and can have different shapes and forms. A globular cluster is a group of tightly packed stars forming a spherical shape. The name is in fact derived from the Latin globulus, meaning small sphere.
Comet: A comet is a celestial body orbiting the Sun that, when close enough to be heated by the Sun’s heat, emits a nebulous envelope called a coma, as a result of released gas and dust, scattered by the Sun’s solar wind. Thus the object appears to have a glowing tail.
Conjunction: A conjunction occurs when 2 or more celestial bodies appear close to each other.
Constellation: A constellation is no more than an arbitrary grouping of [bright] stars. In fact, different civilizations saw different patterns in the sky, thereby having different constellations. Today’s constellations are mainly of Greek origin, with many being named after Greek mythological heroes and creatures, though the Greeks themselves probably borrowed heavily from myths of other civilizations.
Constellations are extremely helpful in guiding us through the universe. 12 "special" constellations form the zodiac.
Crater: A depression in the form of a hollow bowl which results either from a high velocity impact with another object, such as a meteorite, in the case of an impact crater, or, in the case of a volcanic crater, is caused by volcanic activity. The surface of the moon is riddled with craters which are easily visible with binoculars.
Double Stars: A double star refers to a star system made up of two stars which appear to lie together in the sky. The two stars may either be visually linked and only seem to lie together, when in actual fact they may be thousands of light years away- these are called optical doubles - or they may be gravitationally linked and actually orbit each other, as in a binary star system.
Galaxy: A galaxy consists of stars, including planets and other orbiting celestial objects, gas, dust, star clusters and other materials. Our solar system for instance – i.e. the Sun, the Earth and all the other planets and asteroids – forms a tiny part of the Milky Way Galaxy.
Meteor: A meteor is a bright streak of light caused by a small particle of space debris, sometimes no bigger than a grain of sand, as it enters Earth's atmosphere.
Milky Way: The Milky Way is the name given to our galaxy. The name actually refers to the faint hazy white band crossing the sky as seen in dark areas at night, which to the ancients resembled a stream of milk.
Moon: A moon is a celestial body that orbits a planet, and moons are thus sometimes called satellites. Moons vary in sizes, and can be as small as a big asteroid, such as the Martian moon Deimos, or as big as a small planet, like Ganymede, one of Jupiter’s moons, which is bigger than Mercury. The Moon is Earth’s only moon.
Nebula: A nebula is an interstellar cloud of dust or gas in space (the word nebula is in fact Latin for cloud). One of the most famous nebulae seen from Earth is the Great Orion Nebula, found just below the three stars marking Orion’s belt.
Planet: Planets are large celestial bodies that orbit a star. The Earth for instance is a planet that orbits Sol. The Greeks named those stars that seemed to move quickly across the sky "planets", which meant wanderers. Planets are seen from Earth as very shiny stars, though they are easily distinguishable since, unlike stars, they never twinkle. In reality planets do not produce any light of their own, but simply reflect the light of the Sun.
Quasar: A quasar is the bright, active core of a very distant galaxy.
Satellite: A satellite is a small object orbiting a larger one. A satellite can be a natural object, such as a moon or asteroid, or an artificial one, such as a spacecraft.
Sol: Sol is the name given to our Sun.
Solar System: The solar system is a system of celestial bodies made up of the Sun at the centre and other bodies, including planets, moons, comets and asteroids orbiting around it, of which our Earth is part.
Star: A star is a huge gaseous sphere, producing a tremendous amount of heat and energy and visible from earth as a tiny speck of light. Stars are in fact suns and many of them are a lot bigger than our own Sun.
Many of the stars visible from Earth have a proper name, which is usually of Arabic origin, though some have a Latin name. Stars can be referred to by this proper name or by their scientific name, such as that given to them by Johann Bayer, who designated Greek letters to the individual stars of each constellation. For instance, a particular star in the Taurus constellation can be referred to by its proper name Aldebaran, meaning "the follower", or by its Bayer designation, Alpha Tauri.
Sunspot: A sunspot is an area on the Sun’s surface that is darker and cooler than its surrounding area.
Supernova: A supernova is a violent explosion marking the death of a star. A nova is a smaller explosion that can happen repeatedly to the same star for various reasons, and is thus a more frequent phenomenon.
Variable Stars: A variable star is a star whose apparent brightness varies. This may be due to different reasons.
Zodiac: The zodiac is made up of twelve constellations, namely: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius, Pisces.
