The Milky Way near the Grand Canyon, coincidentally the first place I myself ever saw the Milky Way, which didn’t happen until my 20s, as I grew up in urban areas. Image credit: Bureau of Land Management, under a cc-by-2.0 license, via https://www.flickr.com/photos/mypubliclands/16353173238.

What light pollution costs us every night

If you don’t have pristine, dark skies, you might never connect to the Universe. But there’s hope.

“Before we devised artificial lights and atmospheric pollution and modern forms of nocturnal entertainment we watched the stars. There were practical calendar reasons of course but there was more to it than that. Even today the most jaded city dweller can be unexpectedly moved upon encountering a clear night sky studded with thousands of twinkling stars. When it happens to me after all these years it still takes my breath away.” -Carl Sagan

Human vision is ill-adapted to true darkness, but our eyes can provide us with stellar views of the night sky.

Notre Dame de Paris, by night time, seen from the east side. Note how few stars are visible behind it. Image credit: Wikimedia Commons user Atoma.

Since the invention of artificial lighting, however, our views of those natural wonders have diminished precipitously.

A composite image of the Earth at night, with data from 1994/1995. Image credit: Craig Mayhew and Robert Simmon, NASA GSFC, with data from Marc Imhoff of NASA GSFC and Christopher Elvidge of NOAA NGDC.

A view of the Earth at night shows how brightly lit our planet is.