On a lucky Friday night, you might be able to see Jupiter’s bands, and even some of its moons, through the telescope at Fuertes Observatory. But such a clear view of the night sky might soon be harder to get from Cornell.

Construction plans for the new residential halls on North Campus, slated to begin in 2019 once approved, are concerning Cornell astronomers about light pollution at Fuertes Observatory — home to a 96-year-old refractor, the Irving Porter Church Telescope, into which visitors can gaze on clear nights during the Cornell Astronomical Society’s weekly open house nights.

“Undoubtedly the new buildings will contribute to the light pollution,” said Prof. Phil Nicholson, astronomy, who advises the Cornell Astronomical Society. “There will be more lighting out there from windows and external lighting. It certainly won’t get better.”

Plans for the North Campus Residential Expansion project have been under community review since the project’s application report was released in July. Preserving dark skies is one concern among others that have since been raised about the project — and designers are working with the Cornell Astronomical Society to mitigate the light effects as much as they can.

A row of trees already can be seen planted on the north side of Fuertes Observatory. The trees are fast-growing to mitigate lighting from adjacent buildings, according to Chris Davenport, project manager at Cornell Facilities and Campus Services.

To minimize spillover from outdoor lighting, the report also includes plans only to use sharp cutoff light fixtures, which are designed with black hoods to prevent light from radiating upwards except what bounces off the ground.

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Some modifications to existing buildings on North Campus are also underway, including a plan to relocate the outdoor lighting on the roof of Mary Donlon Hall, which has caused issues with night sky viewing, Davenport said.

Davenport said the shades in Appel Commons will also be closed at night. Built less than 500 feet away from Fuertes Observatory, Appel Commons had one of the worst effects in the observatory’s history, because the light fixtures were in direct line of sight from the telescope, according to members of the Cornell Astronomical Society.

This isn’t the first time that concerns about light pollution have been raised at Fuertes Observatory, which was founded in 1917 on a land that was virtually undeveloped at the time.

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Several construction projects on North Campus have previously been decided without the input of the Cornell Astronomical Society, leaving them with no option but to accept rising light levels, according to Nicholson.

While planners in the North Campus Residential Expansion project are now working with the observatory, members of the Cornell Astronomical Society previously said they were concerned that the report from July did not adequately address concerns about the new residential halls’ effects on dark skies.

“It didn’t look like there was very much attention being paid realistically to what bothered us,” Nicholson said.

Nicholson said the report on the light impacts of the new residential halls mentioned the artificial lighting that was visible from Fuertes Observatory, but not their overall effect on the sky.

The report cited findings from a light analysis completed in 2001, which showed “significant existing ambient light levels on the west side of the observatory reaching it from a variety of sources in the City and Town.” It also stated that “the greater contributor of ambient light in the primary south-facing stargazing direction was determined to be lighting at the Sackett Foot Bridge location near Beebe Lake.”

The light analysis did not include quantitative measurements of the light pollution, which Riley Jacob ’21, vice president of the Cornell Astronomical Society, said can be measured using an inexpensive tool — the sky quality meter — that reads the surface brightness of the sky.

What the report misses, Nicholson said, is the fact that even light fixtures that are not visible from the observatory scatter off the haze in the atmosphere, making viewing of “deep sky” objects difficult.

While you could still see the moon and the planets, with increased ambient light pollution, some objects — like the Saturn’s rings — would fade away into the background of the scattered light.

The report also appeared to make an implicit assumption that the observatory only looks into the southern sky, Nicholson said.

However, Nicholson and the Cornell Astronomical Society said they were relieved that planners of North Campus Residential Expansion project were listening to their concerns and that they have since been in contact with them.

“We’re much happier now that they’ll continue to talk to us and seek out our opinion on things that will affect the light and the observatory,” said Karen Perez ’19, president of the society.