March 16, 2009
Share Your Nightscape With The World
GLOBE at night, the international star-counting program, starts on Monday, 16 March, 2009, a key activity during this International Year of Astronomy (IYA2009). Running between 16 and 28 March, it is a digital effort to obtain precise measurements of urban dark skies around the world using sky-quality meters.
How dark is your sky? Do you lose counts of the stars in your nightscape or are you lucky to spot even one? The reason city skies are dull compared to beautiful dark skies in the countryside is light pollution. GLOBE at night is your opportunity to contribute into a worldwide survey that will reveal where in the world you can go to see unspoiled dark skies.Professor Ian Robson, chair of IYA2009 in the UK, says: "Globe at Night is an excellent opportunity for people to get outside and see the night sky. Even from towns and cities it is possible to see Orion, and the information we get from everyone who takes part will allow us to build up a map of light pollution around the UK, and worldwide."
The constellation of Orion, the great hunter, is used to gauge the magnitude of a dark sky (how dark the sky is). Through counting the number of stars in Orion's constellation visible to an unaided eye, you can conclude whether your sky has a measly magnitude of 1 (lucky to see even a few stars, normal in urban sprawls like London) or anything up to magnitude 7 (so many stars you lose count, possible in unspoiled natural beauty like, for example, The Shetland Islands).
Dr Connie Walker, senior science educations specialist at the National Optical Astronomy Observatory, the US national research & development centre for ground-based night time astronomy, said, "We have now passed the point where more than half of the world's population live in urban areas, which are notorious for being excessively lit or badly lit by artificial lights. GLOBE at night is an easy way for people around the world to connect with the increasingly powerful and accepted idea that good lighting saves money; it reduces our greenhouse gases by lowering our use of electrical power; it is better for public safety; and it allows everyone to share the wonders of the night sky."
By Dr Robert Massey, Royal Astronomical Society
On the Net:
- For more information, and to learn how to make and report measurements, see www.globe.gov/GaN
- To make a measurement, you must wait for astronomical twilight (approximately 20.30 in the UK this week) for the sky to be properly dark, look in a south westerly direction and look for three bright stars close together in a straight line. If you can spot it, you've found Orion's belt. Go to http://www.globe.gov/GaN/observe_finder.html for further tips.
- For more information about dark skies, go to www.darkskiesawareness.org.
- International Year of Astronomy 2009
- Royal Astronomical Society