Pag. 001 By Sara Bridges Astronomy is one of the oldest sciences in the world; even the cavemen saw that the patterns and shapes of the stars were predictable and cyclical. But what about you, have you ever looked up at the night sky to see all the millions of stars twinkling back down at you? On first sight it can just look like a mass of stars with no meaning or direction, but if you look again you will notice that these stars make particular pat- terns which are known as constellations. There are eighty eight modern constellations recognised by The International Astro- nomical Union and each of these constellations have a name and an accompanying legend that makes looking at the night sky one of the most interesting and satisfying things you can do for both adults and children of all ages. People throughout the ages have used constellations for a whole manner of different rea- sons. Some farmers used them to help them determine when to plant and harvest in the days before there were calendars. The shapes that the stars seemed to form made it very easy for early farmers to remem- ber their positions in the sky and therefore helped to them recognise when certain seasons were approaching. When they could see Orion high in the sky they knew it was winter, the ancient Egyp- tians prepared for the flooding of the Nile when they saw Sirius rise with the sun. In South Africa the Pleiades star cluster was known as the ‘digging stars’, when they re- appeared in the early morning sky it was time to start digging the ground in order to plant crops. So now fasten your seatbelt, kick and relax while we take a jouney together through space and time and look at some of the mysteries, wonders and beauties of our night sky. Pag. 002 When I was a young girl, I had a fascination with the stars and planets. It started one evening in the back garden when I looked up and saw three stars in a row. I asked my dad and he told me that was it was the constellation Orion and the three stars were his belt. That explanation of Orion and his belt lead to a thousand other questions about Orion and all the other constellations in the sky, many of which I will cover here in my article. At eleven years old my head was spinning with the night sky Frank Drake (above) was born and the universe. My dad bought me books on the subjects and in 1930 in Chicago. He is an would take me out each evening to watch the sky armed with astromomer and astrophysist. He is responsible for SETI and nothing more than a plastic sky map and a pair of binoculars. The Drake Equation. I learnt That same year at school there was a creative writing about the Drake Equation competition and we had to submit an article about any topic after looking up at the early morning sky and seeing the of our choice. I do not remember exactly what the prize Milky Way. The Milky Way is consisted of but I do remember that there were book tokens, a the centre our galaxy and it certificate and a small cash prize. really is something to see. Most of my friends were writing about birds, flags But for all it’s vastness it of the world, football, motor racing, so I decided I would is only one of a billion galaxies submit an article on Astronomy. in the observable universe. I went home with my assignment and began preparing an All the stars that are visible with the naked eye are part article that covered pretty much a lot of the things I am going of the Milkyway. The milky light to cover here but from an eleven year olds point of view. that you can see is caused by My dad bought me a telescope and I prepared a paper on light from other stars in the galaxy that are not visible to my passionate new hobby. I remember the headmaster the naked eye. didn’t like it and there was some controversy over whether I had prepared the article myself as it was a subject The Drake equation was de- vised by Frank Drake in 1962 that he deemed “unusual for an eleven year to take an interest and is used to estimate the in” number of extraterrestial After a few words from my parents, my article was civilisations in our Milkyway submitted. I won second prize, the head said he galaxy. It is used in the “search for Extraterristial intelligence” couldn’t accept it as first prize because in his opinion it was also known as SETI. too well written and it wouldn’t have been fair on the other kids whose ideas were not as “out there” . Frank devised this equation in readiness for a meeting called My parents were unhappy with his reasoning but I was only the Green Bank meeting in Vir- eleven and I didn’t see what the problem was with second gina.The meeting’s prize, I’d won a book token and an award. Job done!! It members were known as the order of the Dolphin wasn’t until I was older that I understood why my and they included people like parents were upset with the headmaster. Choosing a interest astronomers, scientists and in- that was different and writing about it shouldn’t be hushed up, dustrial leaders. played down or subdued. So with that in mind I now present to you my unadulterated, article on astronomy. Not the article that was done by me the innocent eleven year old who couldn’t see past the book token but by me the writer, written from the heart for your pleasure to share with you and encourage you in a science and a hobby that fascinates many people the world over. Pag. 003 To take an interest in astronomy you don’t need to invest in a lot of expensive kit, a good pair of binoculars or a telescope will suffice. To start with you can even try with just some warm clothes and the naked eye. It takes a little while for your eyes to become accustomed to the dark. What I find helps if you are only using the naked eye, is to lie on your back on the floor (preferably in your back garden or yard, and stare up at the sky. At first you may not see much, The equation is only compat- the brightest stars and planets becoming apparent first, but then ible to intelligent civillisations after a few minutes you will notice many thousands more within our galaxy. It doesn’t coming into view as your eyes adjust. apply to intelligence outside of our Galaxy because they are The sky has been used as a navigational tool for too far away to be able to de- thousand of years and if you know your constellations and the tect their radio signals. positions they are in at certain times of the year then you will The Drake equation is: never become lost and will always find your way home. Although it is not a method to get yourself home after a night N=R*fp*ne*fl*fi*fc*L in the pub. N= The number of civilisa- tions in the Milky Way Galaxy whose electromagnetic emis- Constellations for Navigation. sions are dectable. R* = The rate of formation of It is said that using the sky for navigation allowed for the stars suitable for the develop- discovery of America, whether you choose to believe the ment of intelligent life. fp = The fraction of those stars whose with planetary systems. ne = The number of planets per solar system with an envi- ronment suitable for life. fl = The fraction of suitable planets on which life actually appears fi = The fraction of life bearing planets on which intelligent ife actually emerges fc = The fraction of civilisations that develop a technology that releases detectable signs of their existence into space. L = The length of time such civilisations release detectable signals into space. official version of that discovery or whether you believe that it was discovered long before Columbus set foot there, it was very probable that they used the stars for direction. It is very easy to find Polaris (The North Star), it is very close to Ursa Minor also known as the Little Dipper (or in my house as a child “the little milk pan because it looks like a saucepan). Sailors could work out their longitude and latitude by looking at how high Polaris was in the sky. Pag. 004 Some of the most famous voyagers who used this method of Navigation were the Polynesians. These people were sea faring folk with strong and developed navigation skills. They navigated thousands of miles through the Pacific Islands and colonised islands by making long canoe voyages. They did not have any instruments to help them navigate, they used a method called Wayfaring which meant they used the position of the stars, sun, moon, winds and even direction of bird flight to tell them which way to go. It’s been said that the origi- nal numbers that Drake used in the equation back in 1961 The Polynesians built their canoes and developed a were compass called the Hawaiian star compass. It had thirty two R = 10 equidistant directional points around the horizon and each fp = 0.5 ne = 2.0 point was 11.25 degrees from the next.