Last week I saw a talk by Matt Marulla, former president of the New Hampshire Astronomical Society and a contributing author to the latest edition of The Oxford Astronomy Encyclopedia, about light pollution and the “dark sky” – really, lack thereof – phenomenon. (Marulla gives a great talk – funny and incredibly insightful. His 2-minute summary of star formation taught me as much as two weeks of Astronomy 101. He sometimes gives talks at the Discovery Center in Concord; if you get a chance, check him out.)

Light pollution, of course, is a function of excess or bad outdoor lighting. It is slowly wiping out the night sky around the globe – especially in Belgium, of all places. Apparently they really love bright street lighting; check out photos from the space station of Europe at night and you can tell where Belgium is.

One thing that Marulla said really hit home for us in New Hampshire. Sky glow from large cities slowly expands and now, he said, when you’re heading north in New Hampshire, as the sky glow from Boston finally disappears, the sky glow from Montreal starts showing up. Nowhere in the state is truly dark any more.

By coincidence, this is Dark Sky week. Celebrate by getting rid of an outdoor light!