VANISHING STARLIGHT—
Natural Darkness: An Endangered Resource

These images from the first worldwide atlas of artificial night sky brightness (1997) reveal that Maine possesses more star-filled skies than any state east of the Mississippi:

Images by P. Cinzano, F. Falchi (University of Padova), C.D. Elvidge (NOAA National Geophysical Data Center, Boulder, CO). Copyright Royal Astronomical Society. Reproduced from the Monthly Notices of the RAS by permission of Blackwell Science.

Dark regions indicate nearly pristine, naturally dark skies, where thousands of stars can be seen. Yellow designates urban skies with fewer than 1,000 visible stars. White indicates city skies where as few as 20 stars are visible—fewer than can be seen on the American flag.

The rapid pace of development in the United States has made naturally dark skies increasingly rare. It is currently estimated that two-thirds of the U.S. population can no longer see the Milky Way. As a result, many no longer even know what the full splendor of the Milky Way looks like. Many thousands of stars frame the richly marbled dust lanes of the summer Milky Way.

Right: The southern view over Acadia’s Otter Cliffs, taken from Ocean Drive. Note the reflection of starlight on the water. The fully detailed Milky Way reaches to the horizon in this Class 2- 3 sky. Photo by astronomer Tyler Nordgren.

To protect some of the last natural skies in the country, in 2001 the National Park Service took the step of formally recognizing the night sky as a natural resource:

“The service will preserve, to the greatest extent possible, the natural lightscapes of parks, which are natural resources and values that exist in the absence of human caused lighting.”

Its General Management Policy instructs the Service to seek the cooperation of “neighbors and local government agencies to prevent and minimize the intrusion of artificial light into the night scene of the ecosystems of parks.”

Through our unique collaboration with National Park Service scientists, the institute works with communities seeking to protect the star-filled skies over Maine—with the science of innovation. The Institute has forged a partnership with Acadia National Park and Friends of Acadia to measure, promote, and protect  this endangered resource. 

In September 2006 the National Park Service's Night Sky Team used their robotic night-sky camera system to precisely map the amount of light pollution visible from the summit of Cadillac Mountain for the first time (below).

This pioneering full-sky measurement confirms what images from space indicated: Maine possesses more pristine skies that any other state east of the Mississippi. The team declared the summit to be "an excellent East Coast site." Maine can be proud that dark skies are still part of "the way life should be."

For nearly the entire East Coast, night brings an orange glow. Yet east of Mount Desert Island, communities still enjoy a clear view of the Milky Way. Across most of the eastern U.S., costly, glaring, and increasingly manageable light pollution has reduced the universe to a handful of stars.
 

Light pollution is not only an esthetic issue. It is conservatively estimated that over $10 billion worth of electricity is wasted annually on light that is directed skyward, rather than serving a necessary function such as illuminating our homes, highways, and workplaces, or providing security and safety.

The photo above, taken from Cadillac Mountain in October 1985, documents how few lights there used to be in Bar Harbor. The bright concentration of lights on the left of the frame comes from the Bluenose Ferry, the previous ferry to Yarmouth. The gap between the Bluenose and Bar Harbor’s center is now occupied by the brightly-lit campus of the College of the Atlantic. At the far right of the frame, toward the Jackson Laboratory, are pristine dark skies!

The Institute has partnered with the National Park Service, the Friends of Acadia, College of the Atlantic, and a team of volunteers on Mount Desert Island, to place Downeast Maine on the leading edge of endeavors to utilize the newest light-mapping technology, disseminate measurements into the community, and use the data to ensure that our starlit skies are protected.

We hope that our efforts, particularly in Acadia National Park, will serve as a model for the National Park Service's work in other parks. In January 2007, the Friends of Acadia made a commitment to grant the initial matching funds to seed the project; see their letter on our News page.)

We favor a grassroots rather than a "top-down" approach to dealing with the issue of light pollution. Our education programs, already designed to foster an appreciation of the starlit sky, help Maine's schoolchildren—our future leaders—understand the "why" and the "how" of preserving this valuable resource.

• Fran Howley’s fifth-graders at Pemetic School are measuring artificial light in the skies over Southwest Harbor. They share their findings in an interview with Bar Harbor Times reporter Laurie Schreiber ("Eyes on the Sky," January 14, 2008).
   
• Institute President Peter Lord attended the symposium The Night: Why Dark Hours Are So Important, in Washington, D.C. in February 2007. His report summarizes findings from specialists in cancer research, human physiology, security, energy, environmental research, and astronomy, as well as National Park staff. You may download his two-page report as a PDF.
   
• For more information on starlit-sky preservation in Acadia, you may download Peter Lord's article, "Of Curiosity and Starlight," from the Fall 2006 issue of Friends of Acadia Journal.