There are so many stars.
If you have ever been to a truly dark place and gazed up into the night sky, you know what I’m referring to. It’s magnificent. The Milky Way has structure and far-off galaxies can be seen with the naked eye.
Unfortunately, artificial light at night (ALAN) has a negative effect on our ability to see the stars. Most cities and towns produce light pollution due to the dense concentration of outdoor lighting on homes and businesses.
Downtown Pagosa Springs and all along the U.S. 160 corridor to uptown is approaching suburban skies on the Bortle Light Pollution Scale.
So, I was curious. How far away from town must one travel to find pristine dark skies?
We are nestled close to the San Juan National Forest and between the South San Juan Wilderness and the Weminuche Wilderness, so I should be able to find Bortle Class 1 dark skies, right? Would it require hiking into a wilderness area? We didn’t know. So, on June 18, we drove 27 miles out to Williams Reservoir at twilight and waited until 10:27 p.m. to start taking sky quality meter measurements.
Measuring along Piedra Road
To measure how dark the sky is at a location, a handheld sky quality meter is aimed at Zenith (straight up). It measures the brightness of the night sky in magnitudes per square arcsecond.
On a clear, moonless night, we traveled along Piedra Road and measured sky quality at various waypoints.
The method outlined by Dark Sky International is to take four back-to-back readings and use the median value to determine the sky quality. Measurements must be taken on moonless nights with no cloud cover and after astronomical twilight, when the sun is at least 18 degrees below the horizon.
We started at the end of the road by the Williams Creek Trailhead and Palisades Horse Campground. As we made our way back into town, we stopped at many spots, taking readings at commonly known places: Teal Boat Ramp, Williams Creek Campground, Bridge Campground, Piedra River Trailhead, McMannis Road, Jack’s Pasture Road, Coyote Hill Trailhead and Lake Pagosa on Cloud Cap Avenue.
To our delight, we found Class 1 skies. In addition, we could not see any skyglow from the U.S. 160 corridor until we reached the Bridge Campground. How wonderful.
Class 1 skies are excellent dark, with Class 2 being typical truly dark and Class 3 being rural.
The Williams Creek Trailhead and Williams Creek Campground were Class 1 skies.
Class 2 skies included the Teal Boat Ramp, Bridge Campground, Piedra River Trailhead, McMannis Road and Jack’s Pasture Road.
The Coyote Hill Trailhead and Lake Pagosa at Cloud Cap Avenue were Class 3 skies.
Why it matters
Eighty percent of Americans live in places where they cannot see the Milky Way. People travel more than 100 miles from cities in search of dark skies.
I recently attended the Rocky Mountain Star Stare, an annual star party sponsored by the Colorado Springs Astronomical Society. Attendees traveled two hours from Colorado Springs to a pristine dark sky area near Gardner, Colo., called Starry Meadows. People from Denver also made the three-hour trek to Class 2 skies.
Pagosans only have to travel just past Coyote Hill to find wonderful dark skies.
We all should not take this for granted, but should be motivated to preserve it. I was absolutely ecstatic to find Bortle Class 1 skies out by Williams Reservoir. It’s time to go camping.
If you haven’t already connected with Pagosa Sidewalk Astronomers, join our Facebook group or subscribe to our emails on our website.
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