Filter out light pollution at the planetarium

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Sophiya Galanesi / Staff Photo
Two projectors behind the dome immerse the audience into the night sky.

Pierce Science Dome illuminates path to brighter night skies

It has been three minutes since take off. Hands gripped tightly on the seat handles, you brace yourself as the shuttle breaks through earth’s atmosphere. After all the training, the moment to finally see the stars unobstructed has arrived. All that is seen is an endless expanse of stars until Jupiter and Saturn come into view. It’s an unforgettable and unimaginable experience; one that can be found at the Pierce College Science Dome.

The show starts by revealing how little can be seen in the night sky because of light pollution and how much more can be seen without it. Projectors illuminate the unpolluted night sky through red lines that outline the constellations.

This is one of several shows that the planetarium displays to educate Pierce College students, along with the community, about space. The screenings are free to Pierce students and happen every Friday. Every show includes a briefing on light pollution, which for the past six years has increasingly become an environmental issue in Tacoma, Washington, according to the Globe at Night program, an international citizen-science campaign.

Light pollution occurs when people turn on lights at night that shine into the sky and limit their ability to see the celestial body, said Hillary Stephens, Science Dome director.
Two data points were collected with an LM3 over the Metropolitan Market and the Fircrest Golf Club in 2011.
Nine data points were collected with a range between LM0 and LM5 on and around the University of Puget Sound in 2015.
19 data points were collected with a range between LM2 and LM5 in and around North End, Hilltop, Central Tacoma, University Place, Fircrest and South Tacoma in 2019.​

“Pierce is an urban area, and the light pollution is pretty bad, but not as bad as being in the middle of downtown Seattle,” said Stephens. “A lot of the light pollution around here comes from the tide flats in Tacoma, but there are more local sources, too, like the parking lot lights on campus.”

Outdoor lights, such as those near Pierce College, prevent the community from seeing more than half of the constellations, Stephens said. “One of the things this does is wash out the starlight so that in the city you can only see a couple of dozen stars,” she said. “Far away from city lights, you can see around 3,000 stars without a telescope.”

Stephens said the showings try to include information about light pollution – either in the screening itself or through a five-minute video called ‘Losing the Dark’. “The Science Dome is a great place to see what the sky would look like without light pollution,” she added.

Light pollution could have a hazardous impact on one’s health and the environment. Bright lights at night mess with natural circadian rhythms, Stephens said. In addition, many animals use moonlight to navigate. Artificial lights can confuse this navigation process.

To combat light pollution, the planetarium is completely covered in carpet and matte black paint to absorb light that may taint the view of the stars. Two projectors behind the dome immerse the audience into the night sky.

Grace Valdez, a former Running Start student who decided to work as a Science Dome ambassador after completing her general degree, narrated an experience of virtually flying through the Science Dome, while naming the most prominent stars and planets. “A lot of this is just astronomy. If you don’t know anything about it, this is a really friendly place to start,” Valdez said. “This is basically just [a] glorified PowerPoint but [with] planets and space.”

Vijoleta Wallace, a frequent visitor, said she comes here to see the beauty of the stars in a way not possible in Federal Way because there is no other place like it in the area. “The narration is different every time, and it’s just beautifully made.”

The Science Dome, which is in the Rainier building, opened in 2010 when Stephens was hired on at the same time to install a planetarium. Construction ended fall 2012 and opened to the public in January 2013. “The original building plans included a planetarium, but with the recession, it wasn’t in the budget when the building was under construction,” she said. “So, when I got here in 2010, there was just a big empty room.”

Pierce College offers astronomy classes that give students hands-on experience by demonstrating how to use the Science Dome as a resource. Astronomy courses are not part of the Associate of Arts – Direct Transfer Agreement (AA-DTA) degree, and are not required for those pursuing careers in physics or astronomy. Often, universities don’t count these classes toward these majors until students have completed a full year of calculus-based physics, Stephens said. However, the planetarium provides a new way of learning about galaxies that doesn’t require sitting in a lecture hall. After a visit, you may never look at the night sky in the same way.