Unless you've been living a hermit's life on a remote mountaintop for the past decade, you know that light pollution is slowly whitewashing the stars from view. My S&T colleague Tony Flanders has posted several excellent blogs on this topic, such as this one.So how starry is your starry night sky? You can find out easily, thanks to a sky-awareness campaign called Great World Wide Star Count. It'll take just 20 minutes or so, and you'll be joined by thousands of equally-curious skygazers around the globe. Do it on your own, with your family, or as part of a larger group.
All you'll need are a clear evening sky sometime between October 29th and November 12th, your own two eyes, and a set of simple star charts. First, download the handy five-page activity guide (available in 11 languages) and print the star charts. If you live in the Northern Hemisphere, you'll be looking high up for the constellation Cygnus, and its Northern Cross asterism. If you're south of the equator, the target area surrounds the Teapot in Sagittarius. Each of the seven maps shows stars down to a different magnitude limit, plus one for a cloudy sky.
Then, after stepping out under the early-evening sky and letting your eyes adjust to the darkness, match one of the charts to what you see overhead. Step back inside and report what you've found online. You're done!
Unlike many contests, you can enter this one more than once! You might be surprised by how much the sky's darkness can vary from night to night, or between locations only 1 or 2 miles apart.
Want to find out how quickly your eyes adapt to darkness? You can take a measurement as soon as you step outside, followed by another 15 or 30 minutes later.
GWWSC is a managed by UCAR's Windows to the Universe project. The efforts in 2007, 2008, and 2009 netted nearly 12,000 observations from 64 countries. This is a great example of "citizen science" that's helping to raise dark-sky awareness in every corner of the globe.
So, again I ask: How dark is your night sky? Join the Great World Wide Star Count and find out!