Regular readers will be well aware of the growing problem of Light Pollution, and the increasing influence of groups working to restore our night skies. An important part of any such efforts is understanding just how bad the problem is, and Globe at Night gives everybody a chance to help gather this information. The current campaign started yesterday and runs through till 6 March.
So what do you have to do to participate? Not much! First, find your exact location (in latitude and longitude). You can get this from GPS, from a detailed map, or even from such Internet services as Google Maps. Then, go to the Globe at Night activity page download a set of magnitude charts and print them out. Then, wait for a cloudless night within the campaign period (21 February – 6 March 2011). Head outside and find the constellation Orion. Orion was chosen because it’s one of the constellations that most people are familiar with, but if you don’t know it, there are instructions on how to find it on the magnitude chart. Then, simply compare the magnitude charts with the sky around Orion and find which one matches most closely! A heavily polluted sky will show hardly any stars at all, while a very dark location will have so many stars that you’ll actually struggle to recognise any constellations at all!
The final stage, once you’ve found the limiting magnitude (by noting which chart most closely matches your view of the sky), is to go back to the website and report your findings. Easy! so go on – it’s fun, it’s easy and it’s for a good cause.