Light Pollution

Looking south, the Milky Way over the Austin, Texas light dome

As astronomers, even amateur ones, one of our biggest disdains is that of light pollution. No matter what, there is always a source of unnecessary light pollution near you that spoils the darkness of the night. This is probably more the case in the city and suburbs around the world but is becoming increasingly so in rural areas. 

I dragged my family out to a rural area to enjoy some dark skies and have an observatory built under them just north of the town of Liberty Hill in central Texas. It's part of the Hill Country, and we are mere minutes away from lovely drives across rolling hills with wildflowers in the Spring, lots of majestic wildlife and, yes, pretty dark skies. 

The city of Austin and its growing suburbs are to the south of us, with the Killeen area (home to the large US army base, Foot Hood), is northeast, and the smaller country towns of Bertram and Burnet are off to our west. There are small light domes that emanate from Bertram, Burnet and Killeen, but the light coming from Austin to the south has grown steadily over the years. You find ways to work around these, like timing your observations for when various deep sky objects make their journeys across the sky and out of these light domes, or by deploying light pollution filters for both visual and photographic astronomy.

Still, there's a lot of unnecessary light pollution being established by local folks who live in these rural parts. Some it is pretty mind-blowing. From ultra bright, white light security lights that point almost horizontally, to insanely bright driveway lighting or porch lights. A lot of these people don't understand the impact of such lighting. For folks living nearby, they have to suffer through "light trespass", where a neighbor's light lights up their own property and spoils their dark sky view (or even their enjoyment of their local dark surroundings). It has impacts on wildlife, especially during bird migration season. 

The need for security is understood. Everyone wants to feel safe in their own homes and make sure that their property is also secure from would-be evildoers. Makes sense. But it doesn't need to involve all night lighting, or lighting placed in a way where neighboring homes and land is inadvertently affected. Motion sensors help, as do other ways of securing land and property that do not involve excessive lighting. 

Motion-activated lights are your best friend — they only illuminate when needed, deterring intruders without burning all night. Timers and dimmers let you reduce intensity during late hours when full brightness isn't necessary. Strategic placement matters too — focus lighting on entry points like doors, gates, and driveways rather than flood-lighting entire areas. Pairing smart lighting with a security camera system means you can rely less on constant illumination and more on surveillance, giving you both security and a darker, more peaceful sky.

Speaking for myself, I've had to contend with folks who have moved nearby and installed completely unnecessary lighting. On-all-night security lighting, massively bright and high-profile workshop lights. Even extremely bright driveway entrance lighting that does nothing but throw light everywhere (see a photo below of my neighbor's recently installed driveway lights). All very unnecessary. (And this is installed a mere week after explaining to my neighbor that I'd be hosting folks with telescopes out here soon!) I will never understand the need for some people to move out into "the country" and light it up, You can see these driveway lights in the image below.

Inappropriate driveway lighting. 

I keep having discussions, doing things the nice and right way. Folks are typically always agreeable and help out, even the neighbor behind me who set up these driveway lights recently. Still, the issue persists. I read a lot about this on broader community forums as well, so it's not just me. I see a fair few posts from people asking their neighbors to point their lights downward or use warmer bulbs. 

Perhaps it's a perception issue? Security, a nice lit entrance to your property, some other reason I can't think of. It's possible that they genuinely don't consider the impact of their lighting decisions on those around them and the environment more broadly. Not quite sure how you approach that except through constant discussion and requests to "keep the lights down". Maybe one day, they will get it.

Below is a handy guiding graphic that illustrates how you can help to protect the night sky. It's not that hard to implement, and in the long run saves you money and efficiency. It also keeps you in good standing with your neighbors. 

I do see a lot of folks implementing these steps, even local businesses and councils/government. But more and more people seem not to care, and it's going to take a concerted effort to try and protect our dark skies wherever they still exist.\

• Below are some handy dark sky links:
• Dark Sky International
• US Fish and Wildlife Services Dark Skies Initiative
• Texas Parks & Wildlife Dark Skies Program

What do you think you can do contribute to this effort?