TUCSON, ARIZONA--The skies outside this rapidly growing Southwestern city will remain dark for astronomers, at least for the time being, after county officials rejected plans for a $900 million residential and commercial development at the foot of a telescope-studded mountain. The 4 to 1 vote this week by the Pima County Board of Supervisors marks the end of an aggressive campaign by astronomers worried about the effect of lighting from the development on observatories atop Mount Hopkins, 60 kilometers south of Tucson. But they aren't savoring the victory.
"We won this time," says Craig Foltz, director of the 6.5-meter Multiple Mirror Observatory, the world's fifth-largest telescope, on Mount Hopkins. "But we need to get out there and fight to protect the really good sites in the world." Pima County Supervisor Sharon Bronson agrees. "The astronomers made the difference this time," she says, "and I hope they will provide the impetus to amend our light ordinances to make them even more progressive and protective of the industry."
The developer, Fairfield Homes of Green Valley, Arizona, had asked county officials to "rezone" 5700 acres of the undeveloped Canoa Ranch near the mountain's base. A report last fall by company consultants argued that the development would produce less light pollution than would haphazard growth and generate a negligible increase in sky brightness. But a study by astronomers showed a potential 8% to 14% increase in brightness. The debate heated up late last month after the developers' attorney, Frank Cassidy, talked about suing the Smithsonian Institution, whose Harvard-Smithsonian Center for Astrophysics runs one of the observatories on the mountain, for $900 million for "improperly" interceding in the zoning process.
Now that the fight has died down, both sides seem to be taking a longer view. "Nobody wants to hurt the observatory," says David Williamson, president and chief executive officer of Fairfield Homes, although he does not rule out trying again with a smaller plan. For their part, astronomers vow to push for tougher light-emission standards later this year when public officials begin revising the area's pioneering lighting ordinance, first approved in 1972. "What this controversy revealed was that we need tighter controls closer to the observatories," says astronomer Dave Crawford, a founder of the International Dark-Sky Association and a member of the county's lighting code committee.