Simple Stargazing. Anton Vamplew

Чтение книги онлайн.

Adventures in Darkness

      Right, you’ve opened the door and are standing in the garden/yard/field/outback/ savanna/rocky landscape/swamp, etc. gazing up at the night sky searching for something wonderful to appear. How many stars can you see on a clear night? Millions? Squillions? Zillions? In fact, away from light pollution, with a good low horizon, the maximum number of stars you can see at any one time is 4,500(ish). Count them if you don’t believe me. Of course, if you live in a major city, then bright orange skies can easily reduce this number to less than 200, so the darker your location the better.

      A few things to start with…

      Step-by-step guide to stargazing

      1

      Before you go out, check where the Sun rises and sets from where you live. This will give you some idea of where to look when trying to find something in the night sky. Usefully, around 21 March and 23 September, the Sun rises exactly east and sets exactly west. However, in the northern hemisphere during the summer months the Sun appears (roughly and depending on the precise date) somewhere from the northeast and sets somewhere northwest, while in the winter it’s a southeast rise and a sort-of southwest set. In the southern hemisphere, the summer Sun rises somewhere in the southeast and sets somewhere southwest, while winter sees a northeast rise and a northwest set.

      2

      In order to see the most stars you need to let your eyes become accustomed to the dark. This is called dark adaptation. Ten minutes is a good time to sit in the dark without the lights on. Ponder, cogitate and muse over the wondrous spectacle that you are about to marvel at. How many constellations will you find? This process of dark adaptation not only widens your pupils to let in more light, but also allows various chemical reactions to take place in your eyes and activate your light-recepting rod cells. Now you will be able to see all those faint stars.

      Help your dark-adapted eyes by making sure any torch is covered in red plastic.

      3

      Whilst outside in the dark the only way to see where you’re going, or to look at the great star charts in this book, is with a torch. However many you decide you need, each should be covered in red plastic or something similar. The resulting red light, you see, hardly affects your now dark-adapted eyes.

      4

      Grasp this book firmly and, if you are not one yourself, find a responsible adult and venture outside. Adults are very useful indeed for chatting to and for having someone who will marvel at your initial determination.

      Where exactly to begin up there depends on where you live down here. For those in northerly climes, you need to go here (Northerly humans start here) … while southerly humans go here (Southerly humans read this)…

      Empty space – or is it?

      Northerly humans start here

      Just look at the page opposite: it’s covered in what looks like a chaotic pattern of differently sized dots. Nothing could be further from the truth. Each dot is actually a star we can see in the night sky and, just like many things that look like chaos to start with, there’s order within this mess.

      Lurking within these dots you will find a very useful pattern that is probably the best place to start your stargazing quest in the northern hemisphere. This group is known affectionately as the Plough – well, it is in Britain. Moving around our planet, we find that the Plough is called Karlsvogna (Carl’s Wagon) in Norway, the Big Dipper in the USA and the Saucepan in parts of France. This is definitely a good name for the shape, as you can see – a pan with a handle stretching out to the left. Anyone for space beans?

      Now, the Plough is not actually a constellation itself, but part of a much larger group called Ursa Major, the Great Bear – we shall meet it very shortly.

      The Plough is always visible from mid-northern latitudes if the skies are dark and the weather crisp and even. Also, all of its seven stars are quite bright, making it an easy group to find. In order to know which direction to look to find The Plough, you need to have some idea of north, south, east and west. As I said a moment ago, the Sun sets in the west(ish), so look to the right of that and up a bit (that’s a technical term) and there’s the Plough in the north(ish). Easy.

      It’s not long before patterns begin to emerge from the ether. Ether is an old term for the stuff that scientists used to believe filled space – it doesn’t exist, but the idea’s nice.

      Round and round the Plough goes. If you are far enough into the northern hemisphere, this is where you’ll find it at 8 p.m.(ish) at certain times through the year. The left of the diagram is the direction of northwest, whilst the right is northeast.

      Because the Earth is constantly turning, don’t expect the Plough to stay in the same place for long. There’s also our movement around the Sun to consider, which means that each night at the same time the Plough will be in a slightly different position. How exciting is that!? Generally you’ll find the Plough higher in the sky during spring and summer evenings, and nearer the horizon in autumn and winter evenings.

СКАЧАТЬ