Unfortunately, most people today have not experienced the dark skies that were found everywhere in the United States only a generation ago. Instead, they experience the bright night skies of light pollution.
Unless one has lived on a farm, gone to camp away from cities, or belonged to an astronomy club, he or she has no idea what constitutes a dark sky or how much has been lost in just one generation. Light pollution is a pernicious evil that slowly crept up on us.
Older people remember what it was like to see the stars at night, even in cities, and more acutely feel the loss of vibrant dark skies.
In my youth — a very long time ago in the 1950s and ’60s — I was an active amateur astronomer equipped with a four-inch reflector that I purchased for $50 in 1956. Growing up, I could easily observe the Milky Way through the elm trees surrounding my suburban Chicago home. I was more concerned with trees blocking my view of the sky than light pollution. Only gradually did I become aware that the stars were disappearing from urban and suburban areas due to increasing light pollution. Unfortunately, the elm trees and the stars are now long gone from my boyhood home.
In 1985, I received an unexpectedly large tax return. It felt like free money, even though I knew it was money I had overpaid. I decided to buy a piece of land in a dark-sky area for a large telescope, an idea I had talked about for years but had never got off the ground. One thing led to another, and soon I was the owner of 20 acres of land 40 miles southeast of Tucson, Arizona, on a high grasslands plateau at an elevation of 5,000 feet.
Thus, the Grasslands Observatory was born. As the observatory developed, I realized my amazingly dark sky was a very precious and fragile resource, and noticed what seemed like a lot of bad lighting around Tucson. Moreover, the University Medical Center in Tucson converted its old dim globe-style lights to unshielded low-pressure sodium (LPS) lighting. I was aghast. They were bright and spoiled the sky. How could this happen? I asked the hospital director and she informed me that astronomers had actually recommended the new lighting.
At that time, the Dark Sky Office at Kitt Peak National Observatory was headed by Dr. David Crawford, an internationally renowned astronomer known for his work on stellar photometry, who managed the largest telescope on Kitt Peak. Professional astronomers prefer LPS lighting because its somewhat monochromatic spectrum is easy to filter, which is fine with me as long as the light is shielded. Left unshielded, LPS fixtures are just as bad for amateur astronomers as any other poor lighting design. I met several times with Dave Crawford and Bill Robinson, Sr., of the Dark Sky Office to discuss my concerns about their lighting recommendations. What started off as a contentious discussion developed into friendship and a mutual goal of protecting night skies. We exchanged slides, and I began to learn about lighting, light trespass, and light pollution.
I came to realize that light pollution is a relatively easy environmental problem to solve, but no one was doing anything about it. Having recently completed the process of incorporating the Tucson Amateur Astronomy Association as a nonprofit corporation in Arizona, I suggested we form a nonprofit organization devoted to combating light pollution, radio frequency interference to astronomy, and space debris. Dave agreed, and we were on our way. I filed the papers for incorporation and came up with the IDA acronym.
The International Dark-Sky Association, Inc. (IDA) was incorporated in Arizona in 1987 as a tax-exempt, nonprofit organization, exclusively for educational and scientific purposes within the meaning of Section 501(c)(3) of the United States Internal Revenue Code of 1987, and received its 501(c)(3) approval from the U.S. Internal Revenue Service in 1988. Dave incorporated the new IDA goals into his professional work and thereafter, devoting years of his waking life growing IDA into the wonderful organization it is today. IDA has far outgrown its founders and surpassed our every hope for it.
About the author
Tim Hunter obtained a BA from DePauw University in 1966, an MD from Northwestern University in 1968, a BS from the University of Arizona in 1980, and an MSc degree from Swinburne University (Melbourne) in 2006. Currently, Dr. Hunter is a Professor in the Department of Radiology in the College of Medicine at the University of Arizona and was Head of the department 2008-2011. He was on the Arizona Medical Board (AMB) 1997-2006. Dr. Hunter has been an amateur astronomer since 1950, and he is the owner of two observatories, the 3towers Observatory and the Grasslands Observatory. He is also a prime example of someone whose hobby has run amok, spending more time and money on it than common sense would dictate. He has been the President of the Tucson Amateur Astronomy Association, Inc. (TAAA) and a member of the TAAA since 1975. He currently is the Chair of the Board of Trustees of the Planetary Science Institute (PSI).
This article first appeared on the Astronomers Without Borders Dark Skies Awareness blog and later in Nightscape issue #90–91.