I will never forget trekking up Mount Sinai, in Egypt, to watch the sunrise. I did this back in 2002 and will never forget the sight of the stars surrounding the mountain. The Milky Way was clearly visible and I saw stars I have never seen since. It was the darkest sky I have ever experienced and it made me appreciate what the ancient people who first named the heavens must have seen.
We need night time lighting for all sorts of very good reasons, but excessive street lighting, and over-used decorative lighting on fancy buildings, cause light pollution that prevents you from seeing the night sky very well. Look at any image of the world at night from space (like the one above) and you’ll see just how much lighting there is in some parts of the world.
The UK has some dark spots left, but in general we’re one of the worst offenders when it comes to light pollution. As a side note: if you have one of those ‘security’ lights in your garden that turns on when there is movement – just what are you trying to scare off? There may be an astronomer next door cursing you every time a branch swings in the wind.
GLOBE at Night is a dark skies campaign raising awareness of the problem of light pollution. They’re also asking the public to participate and help map the locations of bright and dark spots using a simple star-counting exercise and a nice web app.
Spring is a good time to go and measure how dark your sky is – you can use Leo if you’re in the UK, for example. You then report the findings through the web app and contribute to a global database of dark sky visibility. It is also a good way to figure out just how dark the sky is in your town, and often makes you realise how many stars you’re not seeing.