Reading this article in the MinnPost reminds me again of the threat our star observatories are facing because of the growing problem of light pollution. Pretty lights can certainly be viewed from this once-dark spot, but it’s not the light of distant stars, it’s the light of encroaching city illumination.
At the Onan Observatory in Baylor Regional Park, which is 25 miles southwest of the Twin Cities, people have gathered for years to view the constellations, but it’s becoming increasingly difficult. They come because, like 70 percent of Americans, they cannot see the Milky Way from within the city due to light pollution.
By way of comparison, if you’re in Minneapolis/St. Paul (downtown, that is) you can only see about 20 stars! That’s a shockingly low number, especially when you consider that at the observatory about 2,000 stars can be seen on a clear night.
But the light isn’t just staying within the Twin City limits—it’s slowly creeping toward the observatory as urban sprawl and expansion pushes the city more and more outward. At one time, Onan Observatory was considered a good spot for dark sky night viewing, but not anymore. Today, astronomers, both professional and amateur, have to go at least another hour away from the city to get the best view of the night skies.
We know that this is because of light pollution from urban spaces, but did you know that some are estimating that our country spends $4 to $5 billion annually to send wasted light into the skies that is viewable by astronauts on space stations? Seems pretty inefficient, doesn’t it?
Thankfully, there are people fighting to slow the light pollution problem by pushing for a bill that would introduce a dark sky lighting ordinance in the area. But challenges are making it difficult to get the ordinance approved. For one, the public has little understanding about the problem. Another reason is that there is yet no uniformity when it comes to regulations. Some limit glare (which is more for aesthetics) while others are really trying to limit brightness (where the light is being sent) by enforcing better designs.
I only hope the EPA begins to put some standard regulations in place so that cities can begin to make real progress in limiting light pollution. If they don’t, our observatories could become obsolete in no time at all.