How Come I See Fewer Stars Than I Remember As A Child?

I’m past eighty years old. I remember as a child the stars looking like they were almost on top of us, so close and so bright and a billion of them to boot. Now they look so far away and almost faint. No it is not my eyesight. Have the stars moved away from us to that extent in just 80 years and if so how long before they are not seen at all.
The constellation Orion, imaged at left from dark skies, and at right from Orem, UT. Orem, UT is hardly a large city. This is intended to highlight the fact that light pollution is a problem everywhere, not just in cities with tens of millions of inhabitants. Image credit: Flickr user jpstanley, CC BY 2.0.

The constellation Orion, imaged at left from dark skies, and at right from Orem, UT. Orem, UT is hardly a large city. This is intended to highlight the fact that light pollution is a problem everywhere, not just in cities with tens of millions of inhabitants. Image credit: Flickr user jpstanley, CC BY 2.0.

Originally posted at Forbes!

Unfortunately, the stars haven’t moved, and I believe you that it’s not your eyesight either, because there’s another known and astronomically obnoxious thing that’s happened over the past decades. The amount of light pollution in the night skies has increased dramatically in the past few decades, which is largely because there are a lot more lights, illuminating our cities with no particular care for the darkness of the sky.

The increase in lighting is generally a good thing – well lit streets make people feel safer walking at night, for instance. However, the typical streetlight sends a lot of light up into the night sky, and not just down onto the sidewalks and streets. We also do a lot more lighting up of entire buildings now than we used to, several decades ago, and that light reflects off the building into the night sky. With the advent of cheap, bright LEDs, many of these lights are getting even brighter.

Marina Bay Sands, Singapore, at night. Singapore’s light pollution is so severe that the entire population will never use their night vision. Image credit: Leonid iaitskyi, CC A-SA 3.0.

Marina Bay Sands, Singapore, at night. Singapore’s light pollution is so severe that the entire population will never use their night vision. Image credit: Leonid iaitskyi, CC A-SA 3.0.

The combination of all the streetlights, spotlights, and building lights work together to fade our night sky. The more light pollution there is, the less black the night appears – the sky will only darken to a gray – and the more light pollution, the fewer stars are visible.  The faintest stars fade out rapidly, and relatively soon, there are only a few stars which remain.  

If you make it out to a truly dark spot, the stars of your childhood are still there – literal thousands of them, filling the night sky. But many people who live in cities have no way to get out to see the night sky in a remote area, so the dark, glittering sky is either a distant memory or feels like an experience they will never get to grasp.  This isn’t uncommon. It’s now estimated that 30% of the world’s population cannot see the Milky Way from their homes. This goes up to 80% if you live in North America.

We could make some improvements – the loss of the Milky Way doesn’t have to be permanent. We could choose to not illuminate the sky quite so much while we continue to light the streets for safety reasons.  Shielding the light so it can really only shine down would be an easy first step.  Switching off the lights that light up an entire building – even for a few hours in the middle of the night – would help any would-be meteor shower watchers getting up to watch the sky.  Any improvements we can make will bring the night sky back to everyone.  In the mean time, we’ll have to push for more lighting improvements, so that the only dark skies aren’t just in remote wildernesses.  If you’re ever in a dark area, far from a city, remember to look up.

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