Volunteer astronomer Ron Schmit removed the tarp covering a long, silver-colored telescope and opened the observatory's dome to the skies above Eisenhower Community Center in Hopkins.

Winter nights bring earlier sunsets and colder weather, allowing stargazers to peer through the 60-year-old Lawrence Sauter Telescope. Through its lens are clearer pictures of the moon, binary stars, certain galaxies and planets — the most popular cosmic attractions, which Schmit called enough to open people's minds to the universe beyond.

It has to be enough, because light pollution from the ever-brighter Twin Cities has erased much of the night sky's splendor: the Milky Way, occasional northern lights, the full scope of meteor showers, vast star fields and other stellar objects visible in darker regions.

More cosmic vividness was visible to the naked eye when Sauter, a high school industrial arts teacher, first built his telescope and aimed it toward the heavens in the 1950s. A Hopkins ordinance prohibits light from spilling past property lines, yet one city can't fully

"It's gotten worse, for sure," said Robert Gehrz, a University of Minnesota astronomer, adding the Little Dipper is barely visible in the Twin Cities and he doesn't try to gaze at the night sky from there anymore. "It has to be taken care of in a more global way."

The main organization battling light pollution, the International Dark-Sky Association, has named dozens of areas worldwide as "international dark sky places." Minnesota is not one of them."When you're a kid, you're told to turn the light off when you leave the room, but we don't practice this outdoors," said Scott Kardel, managing director of the International Dark-Sky Association.

Volunteer Bob Shaw pointed out a feature of the night sky during a demonstration for a group of Cub Scouts in the Eisenhower Observatory in Hopkins.

Pushes to hit dimmer switches on cities have gained attention in various parts of the country, but advocates said progress is slow, prompting them to underscore light pollution's impacts on health, the environment and energy savings.

Recent years have seen patchy progress against light pollution. Rep. Phyllis Kahn, DFL-Minneapolis, said she fought to include light pollution provisions in a 2007 energy bill, including one to draft a model ordinance for Minnesota municipalities. But it was passed without funding, according to Curt Yoakum, a legislative spokesperson.

Also, the Minnesota Pollution Control Agency has only sporadically tackled light pollution in the past, and though bonding bill-funded construction projects must adhere to energy-efficient lighting rules, there is wiggle room for facilities needing more outdoor illumination.

Some Minneapolis skyscrapers, including IDS Center and Wells Fargo Center, have voluntarily participated in the Lights Out Twin Cities program promoted by the Minnesota Department of Natural Resources to protect bird migrations, and a recent law requires state-owned buildings to do the same.

But the nature of light pollution renders anything short of statewide reduction somewhat futile. David Faulkner, a member of the Minnesota Astronomical Society, said he and others of the organization's 450 members travel more than two hours from Minneapolis for stargazing at the Long Lake Conservation Center.

Eisenhower is one of a number of observatories nestled in heavily-lit cities, including the one atop Tate Hall at the University of Minnesota's Twin Cities campus and another at the University of Minnesota Duluth.

Eye-opening experience

The Eisenhower Community Center installed shielded light fixtures in its parking lot, a measure that Schmit said created "an island of dark" around the telescope's field of vision. On clear nights, he ushers groups of people up a narrow hatch leading into the chilly observatory dome to educate them about the solar system.

"Just looking through this telescope will open your eyes to ideas you've never considered before," he said.

Still, most people aren't astronomers, prompting public advocates to highlight other benefits of reducing light pollution.

Studies show lights at night can also affect sleep patterns and mental health and alter genes that regulate tumor growth and suppress melatonin — a hormone produced only at night.

Light pollution's effects also extend to the natural world, advocates argue, altering ecosystems and confusing animals like migrating birds that smack against windows and turtle hatchlings unable to find the water by moonlight.

A chief benefit of shutting off lights would be energy savings, since about 22 percent of U.S. energy is used for lighting, with 8 percent of that consumed by public outdoor lighting, according to the International Dark-Sky Association.

"How could you not do something to reduce energy use, lower costs and reduce emissions?" Kahn said. "Once the public understands it, it causes no inconvenience to people."

Jeff Hargarten • 612 673-4642