The price of a starry, starry night

By Larry O’Hanlon

On a clear night in Honolulu you can see about 20 stars. Just 20. That’s out of a galaxy which is home to more than 200 billion stars. In human terms, if Bill Gates wanted to use every last one of his billions of dollars to buy up the galaxy, he’d need to get them for the bargain basement price of a quarter a piece or he’d be unable to afford them. The same price for all the stars in Honolulu’s sky will cost you five bucks. You might say Honolulu is star-poor.

Away from city lights, on the other hand, there is a vast treasure chest of stars to be had on a cloudless night. Residents of rural Hawaii are privileged to see the twinkling of about 2,000 stars, plus the softer glow of many millions more too far away to distinguish as points of light. The light of the rest of the Milky Way galaxy’s billions of stars, as well as billions of more distant galaxies beyond our own, can’t be seen without the aid of telescopes.

A night sky free of manmade light pollution is, of course, among the reasons so many astronomical observatories are located on Mauna Kea. It’s also the reason this island has so many of those odd yellow streetlights, which minimize light pollution.

“Mauna Kea has natural attributes that make it the best place on Earth to undertake the detailed study of our Universe, and controlling light pollution preserves this key resource for Hawaii and all of humanity,” said Taft Armandroff, director of W.M. Keck Observatory in Waimea.

But astronomers aren’t the only ones who need the dark. On the island of Kauai poorly shielded lights have led to the disorientation and deaths of birds, including the endangered Newell’s shearwater. According to the International Dark Skies Association, light pollution has been shown to disorient migratory birds and hatchling sea turtles, disrupt mating behaviors in fireflies and frogs, and interfere with communication in species ranging from glowworms to coyotes. Even low levels of light at night have been linked to breast cancers in rats, suggesting that human health could also be affected.

There are also, of course, plenty of people who simply like starry nights and aren’t astronomers; people who want to see a sky unlike anything they can find at home in Los Angeles, Philadelphia, or Chicago. For these people Hawaii’s dark skies are a vacation destination.

So it’s good to hear that the Hawai’i State Legislature is moving forward with a bill to help ensure our gorgeous night skies are not drowned out by light pollution. The modestly titled bill, “Relating to Light Pollution” (SB1493 SD1 HD2), describes a “starlight reserve strategy” which will require all new and replacement outdoor lights be “full cutoff” which do not shine upwards into the sky as of July 1, 2013. The bill eloquently makes the case:

“..[T]he night sky is a tremendously valuable natural and cultural resource for residents of Hawaii, and for visitors to Hawaii. The dark night sky has tremendous scientific value for astronomy, and is vitally important for endangered species in Hawaii including birds and turtles. Mauna Kea, on the island of Hawaii, is the best astronomical observatory site in the northern hemisphere, and arguably the best site on Earth.

“Unnecessary light pollution is threatening the dark night sky over the Hawaiian islands. This light pollution includes sky glow, energy waste, glare, light trespass, visual confusion, and environmental harm. Light can travel enormous distances through the Earth’s atmosphere, and therefore does not respect county boundaries. Light pollution therefore spreads across the entire State and must be addressed using statewide legislation. Furthermore, endangered species that are affected by light at night live on many of the Hawaiian islands [sic].”

Finally, for those people who are not swayed by endangered species or the mysteries of the universe, there is the matter of cold, hard cash. Reducing outdoor lighting, and switching to light fixtures that shine in narrow wavelengths – like those yellow street lamps — means big electricity savings. This, in turn, helps to preserve many of natural qualities that draw visitors to the islands and power the tourism industry. There are also the economic benefits of all those astronomical observatories.

“Astronomy is a clean industry with an economic impact of $150-$200 million per year in Hawaii,” Armandroff explained. “Preventing light pollution is an effective way to maintain Mauna Kea as the world leader for astronomy.”

In other words, a star-buying billionaire would be one wise businessman, because in Hawai’i the stars are paying dividends.

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Science writer Larry O’Hanlon is the communications and public programs officer for W.M. Keck Observatory