April 13, 2022
'Smart' outdoor lighting system envisioned for Rothney Astrophysical Observatory
Let there be light! But at the Rothney Astrophysical Observatory (RAO), not too much light — just enough to do the job.
The University of Calgary’s popular observatory, which hosts thousands of stargazing visitors each year, needs a lighting system for its unlit outdoor parking area, says Dr. Phil Langill, PhD, director of the RAO and a senior instructor in the Department of Physics and Astronomy in the Faculty of Science.
However, the typical bright lighting seen at shopping centre and grocery store parking lots or along streets won’t work.
The RAO, perched on a hilltop near Priddis just south of Calgary, is a “dark skies” observatory for viewing the stars and other celestial wonders.
“If we tried to put up the typical lighting style in our parking lot, our telescopes would not see anything at all in the sky,” Langill says.
The RAO is a working scientific research facility that trains students and, through several public outreach programs, is also a place where teaching and research connect with public education and community engagement.
The most fun thing we do is invite people to come to the observatory and use their eyeballs to see the sky. With a brightly lit parking lot, people wouldn’t even be able to see anything with their eyes.
What the RAO needs is a “smart” lighting system, Langill says. It would provide just the right amount of light to make the observatory’s parking area safer and enable visitors to navigate to and from their vehicles.
The lights would need to be mounted on short light standards no higher than the hood of a sedan, and each light would have shields to direct light straight down where it’s needed.
All the lights would be dimmable and have motion sensors, so that most of the time they’re off and only come on when visitors are navigating the parking area.
The plan is to power the smart lighting system using solar and wind energy, backed up by battery storage, Langill says.
The RAO has an interpretative centre with a roof slanted toward the sun that would be ideal for solar panels, he says.
Colour of light is important
It is not only the direction and brightness of the light that matters, but also the colour, Langill notes. “Light particles are like ping pong balls and they just bounce off everything.”
Photons of blue light, especially, are “super-scatterers” that bounce around the atmosphere and travel farthest from where the light originates.
For the RAO’s sensitive telescopes, he says, “One bright light, especially if it’s blue, close to the observatory has as many negative effects as one thousand lights 10 kilometres away.”
In addition, studies show blue light constricts the pupils in the eyes, which lowers the amount of light entering the eyes and actually makes it harder to see at night.
So the RAO’s smart lighting system definitely won’t be utilizing blue light.
Being able to use energy-efficient LED lights would reduce energy costs. However, LED lights initially were super-blue, although the technology has since advanced and other colours may now be available, Langill says.
Smart lighting system would be one of a kind
The RAO has two outdoor parking lots, an upper level that can accommodate about 40 vehicles and a lower level for about 30.
Langill says he’s not aware of any public astronomical observatory in Canada that has the kind of smart lighting system envisioned for the RAO.
That makes it difficult to estimate the capital and operating costs, especially if the system can’t be built with off-the-shelf components and needs to be custom designed and built at the University of Calgary.
Not only would smart lighting make the RAO’s parking area safer and ensure a high-quality experience for visitors, the plan is also to showcase the system as a learning tool and real-world project to inspire others.
Most people don’t give much thought to the outdoor lighting they use and its impact on the night sky, Langill says.
“I think there’s an educational opportunity,” he says. “Every time we have a public event here, we’re going to be showing our new smart lighting system to hundreds of people. Who knows where it will lead?”
Giving Day April 21 is your chance to contribute
With University of Calgary Giving Day coming up on April 21, and with the RAO celebrating its 50th anniversary, Langill is hoping a donor or group of donors will contribute to the smart lighting project.
Ideally, the system would be installed over the summer so it’s ready for this fall when the days start to get shorter.
Says Langill: “We have to reverse the lighting trends we see in Calgary and other cities, so that the stars come back and people remember to look up.”
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