For more than 100 years, scientists around the world have confined Mount Hamilton to sitting inside a large, white dome and gazing into space. From its faintest rays, they learned stories of stars exploding in the distance and finding entire solar systems like our own.
But those hazy cosmic messages can be a little harder to read.
On Wednesday night, the San Jose Airport Commission is meeting to discuss the proposed installation of two double-sided digital billboards along Highway 101 on the Mineta San Jose International Airport campus. The two screens are set to face directly the University of California’s famous Lick Observatory on the hillside above San Jose, potentially overturning the city’s decades-long billboard ban and covering hidden precious vistas from the depths of the universe.
“We’re detecting new worlds from right here in Santa Clara County,” said Paul Lynam, an astrophysicist at the Lick Observatory. “Access to these facilities is very important to people and astronomy lovers around the world. Losing those abilities would be a betrayal. “
For decades, the city commissions of San Jose and Santa Clara have worked hand-in-hand with the UC Observatory system to reduce light pollution – using special street lights and visors to protect the atmosphere. night. In 1985, San Jose officials issued a citywide ban on the construction of new billboards, citing the glittering towers as unsightly and an unnecessary distraction.
Residents and astronomy buffs alike worry that the new billboard proposal could overturn this historic ban, opening the floodgates for additional night-lighting ads.
“Two billboards, would that paralyze the Lick Observatory? Is not. But it’s the nose of the camel in the tent,” said Matthew Shetrone, deputy director of the UC Observatory. “We don’t want to see San Jose’s complexion changed to something that looks like Las Vegas.”
For the sake of astronomy, the concern about billboards is twofold. First of all, they’re bright – like, very bright. And they are oriented more or less vertically, the blinding panel not only illuminating the road but also the sky.
“Someone half a mile away would see this as bright as a full moon,” Shetrone said.
Worse is the type of light that is emitted. Unlike the sodium vapor street lights the city installed decades ago (at Lick’s request), the LEDs powering the new digital billboards release a wide range of wavelengths to create their white light.
This makes light pollution harder to filter out for astronomers, and it also allows blue light to scatter through the atmosphere and beyond.
The proposal incorporates some of the Lick Observatory’s previous recommendations, like tilting the board down a bit. But the guidance has largely been taken out of context and is now out of date, Lynam said.
While potential observational challenges are certainly a concern for astronomers, they insist that public safety is their primary concern. After all, light pollution has also been linked to distracted driving, ecosystem effects and even an increased risk of cancer, Shetrone said.
These airport billboards were originally proposed back in 2018 and the movement has been met with repeated opposition – mainly from concerned citizens.
“I don’t know why this continues despite the huge outcry against it,” says Lynam. “Are you mortgaging the future lifestyle and environment and enjoyment of the night sky by the people of the South Bay to increase airport revenue by a fraction of 1%?”
The war reflects a larger societal trend toward brighter night skies, slowly masking the expressive twinkles once seen from white domes around the globe. For now, Lick astronomers are counting on public support to keep the billboard ban alive.
“San Jose and Santa Clara counties have always been really respectful, responsive, and understanding,” said Lynam. “I hope that the current billboard problem is just a bright spot in that long-standing partnership and hopefully just a misunderstanding.”
https://www.mercurynews.com/2022/01/25/south-bay-astronomers-fear-proposed-airport-billboards-would-threaten-night-viewing/ Lick Observatory astronomers fear light from new LED billboard