Rediscovering the Milky Way

Only 1 in 5 people in North America live in a place where they can see the Milky Way. That’s the staggering finding of a new paper in Science Advances, in which the authors painstakingly matched satellite images with ground measurements of light pollution around the world.

Generally, that light pollution is something astronomers complain about and the rest of us would ignore. But as observes, light pollution interferes with nocturnal animals and migrating birds, and can also interfere with people’s circadian rhythms.

It also separates us from our history and the world around us. The Milky Way is a part of every culture’s mythology, as are tales of the stars and how constellations came to be. In Oakland, where I live, it’s sometimes barely possible to make out the Big Dipper, let alone track the other planets or spot a comet. It’s barely possible to see the changing constellations that marked the seasons for most of human history. Students who haven’t traveled to wilderness areas may never have seen the Milky Way, never knowing what they’re missing.

By a lucky coincidence, just days before this historic survey of light pollution came out, Grand Canyon National Park and the International Dark Sky Alliance announced plans to make the Grand Canyon a Dark Sky Park. Outdoor lights at the rim will be reconfigured to direct the light down, not up into the hazy sky, and the park will take other steps to make sure the night sky over the Canyon remains as pristine as the landscape itself.

On the river with NCSE’s annual rafting trip, the only light pollution you’re likely to encounter comes when other rafters neglect to put a red filter over their flashlight. On clear nights, you can see the Milky Way just fine, and a decent pair of binoculars lets you explore the universe from your sleeping bag. Alas, my experiments with astrophotography on last summer’s trip were a bit too blurry, but I’ll be trying again this year.

There are still a few open spots on the raft this summer, if you’d like to spend 8 days with me and Steve Newton (and NCSE’s own Ann Reid and Rae Holzman!). We’ll sleep under the stars, ride through the rapids, lay hands on the Great Unconformity, look for caddisflies, and along the way we’ll contrast the scientific and creationist explanations for what we’re seeing.