England launches 'cosmic census' to combat light pollution
In an effort to discover and preserve vestiges of the English night sky unspoiled by light pollution, the British Astronomical Society has joined forces with The Campaign to Protect Rural England (CPRE) to launch the great Star Count of 2019.
“A dark sky filled with stars is one of the most magical sights our countryside has to offer,” Emma Marrington, dark skies campaigner at CPRE, told The Guardian. “Increasingly, however, too many people are denied the opportunity to experience this truly natural wonder.”
A nighttime view of the United Kingdom as captured by NASA and NOAA’s Suomi NPP satellite. (Photo: NASA)
In a 2015 study aptly called Night Blight, the CPRE used nighttime satellite imagery to conclude that only 22 percent of England experiences night skies completely untouched by light pollution. This number pales in comparison to Wales (57 percent) and Scotland (77 percent), which benefit from significantly lower levels of population. Not surprisingly, 19 of the brightest 20 districts are London boroughs, while nearly all the darkest counties skirt the edges of England’s borders.
In this long exposure, light pollution from St. Ives casts a orange haze in the night sky above the mysterious Men-an-Tol, one of the best known megalithic structures in Britain. (Photo: Matt Cardy/Getty Images)
While counting stars might sound like an overwhelming, albeit wonderfully unusual way to spend a chilly February evening, the campaign isn’t actually asking participants to go mad counting the Milky Way. Instead, until Feb. 32, the goal is for British citizens to go outside and look for the constellation “Orion” with its four corners and famous three-star belt.
“Take a few moments to let your eyes adjust, then simply count the number of stars you can see within the rectangle made by the four corner stars,” the group writes. “You should not count the corners, but you can count the three stars in the middle — the belt.”
Because the three stars in Orion’s belt — Alnilam, Mintaka and Alnitak — glow fairly bright, they’re generally an excellent starting point for a star count campaign, even under some of the worst light pollution conditions. It’s when you start recording the stars within its four corners that the impact of light pollution begins to skew results wildly from region to region.
As shown in the time lapse below of various levels of light pollution in the U.S., Orion looks a lot different under the lights of San Francisco than it does under the perfectly dark conditions of Goblin Valley State Park, Utah.
According to the results from the 2014 Star Count, 59 percent of the 1,000 participants could see 10 stars or fewer within the four corners, an indicator of severe light pollution. By comparison, those under dark skies — a number that amounted to only 4 percent of participants — could pick out 30 or more stars.
Once you have your tally of the stars within Orion, submit them through the CPRE website. The data will then be mapped and the results used to help inform future campaigns to curb light pollution. Some of the easiest fixes, according to dark sky proponents, come from adding shielded light fixtures, motion sensors and programmable LEDs. Through activities like this national star count, the group is hopeful that people will simply take the time to look up and appreciate the increasingly fleeting beauty of their heads.
“You don’t have to be an astronomer to be influenced by a view of a starry night,” Christopher Luginbuhl of the Flagstaff Dark Skies Coalition told Sky and Telescope. “And you don’t have to know how far a star is to get the basic message that the universe over your head has meaning and perspective to give to human life.”