What can we do about light pollution?

Light pollution can be a scourge for astronomers. But there are ways for the individual astronomer to reduce its effect on our observing sessions.

The glare of light pollution can be a menace for amateur astronomers. Credit: Steve Marsh

We often extol the virtues of the night sky and the many treasures our binoculars and telescopes will reveal. But spare a thought for the many who don’t have dark skies but are blighted by that enemy of the astronomer, light pollution.

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The relentless waste of upward-pointing or misdirected light just seems to keep on getting worse, even despite the best efforts of campaign groups such as the Commission for Dark Skies.

They do tremendous work trying to educate and enlighten anyone who will listen as to why it is so important to reduce the scourge of light pollution.

And it is not just to give us dark skies so we can see the Milky Way in all its glory or view distant galaxies and the like, but to reduce our global emissions too.

Many of us have to contend with varying degrees of light pollution, from orange sodium skies to the white skies brought about by the many intense white ‘security’ (or should that be insecurity?) lights that seem to blast out white searchlight beams regardless of who wants to see the light or not.

So, what can we do? Well, we can support the campaign groups on the one hand, but there are practical ways to minimise or get around the light pollution.

For those suffering from sodium style lighting then there are visual and imaging filters that do help: indeed for imaging, narrowband filters are a way to go and we often see such amazing images in both our monthly Gallery in the magazine and submitted for the Astronomy Photographer of the Year competition.

Often if a streetlight is disturbing you it is worth approaching your council to ask if it can be shielded in your direction.

If a neighbour’s security light is an issue then you could always ask them around for a viewing session.

You’ll be surprised at how often they are shocked at the effect of their light and then go back and do something about it.

The lights from towns and cities can blot out views of the night sky. Credit: iStock
The lights from towns and cities can blot out views of the night sky. Credit: iStock

When I was back living with my parents in a hamlet with no streetlights, a neighbour up the road and due south of me installed a humongous bright light pointing straight down at us.

He’d often mention wanting to look through my telescope, so I gave him a call and invited him down, knowing full well the light was on.

He happily came down as he could easily see the way then tried looking through the scope but had to shield his eyes from a certain bright light.

He had no idea it could have such an effect and immediately walked back up, turned off the light then did the natural thing and used a torch to come back down the lane.

And the reason for the light? Not for security, but for when he let the dog out to do its business, and he usually forgot to turn it off once the dog was let back indoors!

After his little observing session, he insisted I give him a call, regardless of the time, if the light was left on. Later in the year he discovered his electricity bill had dropped a little – all down to turning off that one over bright light!

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Of course, there will always be exceptions and you can’t win every battle, but if you want to get the best out of your equipment then surely it is worth the effort of trying.