For thousands of years travellers would use the stars for navigation.
Here in the southern hemisphere we can easily find our way when lost at night by learning to find the constellation of Crux (the Southern Cross) and the Pointers (Alpha and Beta Centauri).
Draw two imaginary lines, one through the Southern Cross and the other perpendicular to a line joining the two pointer stars. Where these lines meet is known as the Southern Celestial Pole. Look directly towards the horizon below this point and you will be facing south.
Recently I gave a talk, educating the general public about light pollution and the effects on Astronomy, Wildlife, People and the Economy.
I was a little shocked to find that 2/3 of the audience had never even been to a dark site or even seen the Milky Way.
For thousands of years people would look up at the night sky and be inspired by the absolute immensity of the cosmos. Now due to the increasing number of poorly shielded and misdirected city lights we generally don’t look up any more, when we do, we are lucky to see a few hundred stars.
Lets get some figures to get a sense of scale. Astronomers have calculated that there is on estimate 100 – 400 billion stars in the Milky Way alone. This is based on determining the mass of the galaxy then extrapolating the number of stars based on an average mass. As we can safely assume that the majority of stars are smaller red and brown dwarf stars the number would be closer to the 400 billion.
The glow from these stars and the ionised gas in the disk of the Milky Way allows us to see the spectacular view of the sky as shown in the image above but to see this you need to get out of the urban sky glow and into some dark country locations.
The next obvious question you are going to ask is “where can I go to get dark skies?”
To get the truly dark skies in Perth you will want to drive east for a bit over two hours to get to somewhere such as Pingelly or Cunderdin, however for general purposes anywhere in the blue to white region of the map below will provide you with a fantastic view of the night sky.
A favourite site of mine is the Avon Valley National Park which is still in the blue region and only about 45 minutes from Perth.
One final word of warning if you are planning on a dark sky expedition. While you can get away from the city lights, you will be hard pressed to get away from moon light so try to organise your trip around a new moon to maximise your experience of the dark night sky