The Wonder of Night
<span style="font-size: 1.5rem;" >We don’t get as much out of the night sky as past generations. Our ancestors used stars for navigation, sailing across whole oceans with only their knowledge of the heavens as a guide. They found mythical beasts in the stars that we now call constellations. Skygazing was a way of life, not just a source of wonder.</span>
The Gregorian calendar still used by Westerners was developed from a lunar calendar which tracked the moon’s phases from full moon to new moon (though our calendar doesn’t correspond to the moon’s cycles anymore because of endless tweaks over the centuries1). In the modern world, by contrast, we look at the stars when we go camping… and that’s about it. Media and devices outcompete the celestial realm for our attention. Stargazing and developing a relationship with the night sky isn’t something that is a given, the way it was for our ancestors; it’s something one has to decide to do.
Maybe the biggest reason we’re not as connected to the night as people were in the past is that for most of us, there’s just less to see these days. Those of us in cities face light pollution blocking out most of the stars. What is light pollution? Light will travel forever until it hits something. All the street lamps and headlights and restaurant signs lit up at night are broadcasting their own light, making a haze in the night sky. When you (try) to look up at the stars, this “sky glow” bombards your eyes with random light from sources on the ground. In major cities, there’s often not much night sky left at all – the stars, planets, and comets are all blotted out by the haze of stray photons. Urbanites get the sun and the moon and nothing else.
Unfortunately, light pollution does more harm than just keeping us from soaking in starlight. Frogs croak as part of a mating ritual, but they only croak in the dark. Some birds (like owls) or mammals (like opossums) only hunt in the dark. Light pollution throws these animals off rhythm, so they don’t breed and feed as often as they normally would, and scientists have found that this measurably reduces their numbers.2 Meanwhile, animals that sleep at night (humans most definitely included3) can have their sleep chronically disrupted by all this “visual noise.”
You can actually help scientists track light pollution. Researchers developed the Loss of the Night app that makes measuring skyglow a game – it will guide you to point your app at specific stars, which you then mark as visible or invisible to your eye. Geoscientists can’t put light sensors in every town in the world, so these kinds of Citizen Science projects are vital for tracking the impact of light pollution on animals.
You don’t need to buy an expensive telescope, wait for an event like a lunar eclipse, or spend time memorizing dozens of constellations to start appreciating the night sky—you just need to look at what’s there and be open to feeling wonder. Go outside tonight. If you’re in an area with a lot of light pollution, drive out a bit from the city center to get somewhere actually dark. Just look; it’s meditative. Notice how some stars are brighter than others. (Is it because the bright-looking stars are actually brighter, and so maybe hotter—or just because they’re closer to us than the dim-looking stars?)
One of the most fun ways to develop a relationship with the night sky is to watch a meteor shower. Stare up into the night long enough, and you’re bound to see the bright streak of a shooting star flash and then vanish. Or, travel to a dark zone and enjoy the yearly Perseid meteor shower. These shooting stars aren’t really stars—they’re chunks of rock or ice from space, or maybe even bits of junk discarded from human space stations or satellites that flash as they burn up in our atmosphere. Groups like the American Meteor Society track meteor showers and tell you where to look—all we have to do is look up.
1 Gregorian Calendar, Wikipedia.
2 Light Pollution Can Harm Wildlife, International Dark Sky Association.
3 Sleeping in a room even a little bit of light can hurt a person's health, study shows, National Public Radio.