The masking of the heavens dims our age of enlightenment

The masking of the heavens dims our age of enlightenment

New York City from above • NASA (Public Domain)

Originally published 16 April 2002

A few weeks ago I flew from Mia­mi to Boston on a clear, dark night.

The plane took a course just east of the North­east Cor­ri­dor — Wash­ing­ton, Bal­ti­more, Philadel­phia, New York City, and on to Boston. Above, stars glis­tened in a jet black sky. Below, cities glis­tened in a twin­kling sea of amber and aqua light.

New York City was espe­cial­ly stun­ning, with its string-of-pearls bridges and lacu­na of dark water, ablaze in a bil­lion points of light.

I’d seen it many times before, of course, but still it took my breath away. New York City at night from 30,000 feet must be one of the most beau­ti­ful sights on earth.

I felt priv­i­leged to see it.

And then I thought of all those mil­lions of peo­ple down there in that sea of light who have nev­er seen the Milky Way, nev­er seen an inky dark sky arch­ing from hori­zon to hori­zon, nev­er seen the zodi­a­cal light, the Lit­tle Cloud in Can­cer, the Dou­ble Clus­ter in Perseus, or the faint core of the Great Galaxy in Andromeda.

Just a few weeks ear­li­er, from a dark Caribbean isle, I had caught a glimpse of Comet Ikeya-Zhang with the unaid­ed eye, and then a week lat­er through a small scope I saw the comet brush the star Mirach with its wispy tail. I would­n’t have seen these things from Wash­ing­ton, Bal­ti­more, Philadel­phia, New York City, or Boston.

The light I saw from 30,000 feet serves no use­ful pur­pose. Prop­er­ly designed light­ing would direct illu­mi­na­tion down­ward, where it is need­ed for con­ve­nience and secu­ri­ty. The upward-direct­ed light I saw from the air­plane is scat­tered through the atmos­phere and obscures the stars for observers on the ground. It has been esti­mat­ed that in the Unit­ed States alone we waste more than $1 bil­lion a year on light that does noth­ing more than illu­mi­nate the bot­toms of airplanes.

But my god it is beau­ti­ful — a spec­tac­u­lar­ly gor­geous, prodi­gious­ly extrav­a­gant waste. A bil­lion dol­lars worth of ener­gy that trans­forms the night­time plan­et into a won­der­ful and ter­ri­ble work of art.

About two thirds of the pop­u­la­tion of the world and 99 per­cent of peo­ple in the con­ti­nen­tal Unit­ed States and West­ern Europe nev­er see a tru­ly dark, star­ry sky from where they live because of light pol­lu­tion, say Pieran­to­nio Cin­zano and Fabio Falchi, both of the Uni­ver­si­ty of Pad­ua, Italy, and Chris Elvidge of the Nation­al Geo­phys­i­cal Data Cen­ter in Boul­der, Col­orado, authors of a new World Atlas of Arti­fi­cial Night Sky Bright­ness.

Based on satel­lite sur­veys from space, the atlas shows the bright­ness of the night sky on earth. The East­ern Unit­ed States is a blotch of arti­fi­cial light, as are Europe and Japan. Some places one might expect to be dark — the Falk­land Islands or the Sea of Japan, for exam­ple — are pol­lut­ed with light from oil pro­duc­tion, nat­ur­al gas flares, or night fishing.

What’s to be done? Use more envi­ron­men­tal­ly sen­si­tive light­ing, of course, and many com­mu­ni­ties have begun to man­date change. Nev­er­the­less, it seems inevitable that an increas­ing frac­tion of the world’s pop­u­la­tion will nev­er expe­ri­ence a tru­ly dark sky.

Even on the island where I saw Comet Ikeya-Zhang, the dark­ness is threat­ened. The elec­tric com­pa­ny is putting up street lights along the island’s one main road, lights that fill the sky with a sick­ly orange glow. They call it progress, and the local res­i­dents gen­er­al­ly applaud, but soon the island will emerge as a glow­ing dot on satel­lite images of the night­time earth from space, and island chil­dren will grow up nev­er hav­ing seen the Milky Way.

Does it mat­ter? I sus­pect the next gen­er­a­tion of islanders would hap­pi­ly sur­ren­der the dark night sky for the tech­no­log­i­cal won­ders that accom­pa­ny those offen­sive street lights — auto­mo­biles, cable tele­vi­sion, the oppor­tu­ni­ty to trav­el in high-fly­ing jets, and the chance to see the breath­tak­ing beau­ty of New York City from 30,000 feet.

And who am I to tell them oth­er­wise? I have all those things, plus the afflu­ence to trav­el to their island to see the Milky Way. In the future, those of us who val­ue dark skies will have to trav­el fur­ther afield, to west­ern Mon­go­lia, for exam­ple, or sparse­ly pop­u­lat­ed islands in the Pacif­ic Ocean. Some­day there will be Inter­na­tion­al Dark Sky Reser­va­tions, iso­lat­ed ocean­ic islands, or remote cor­ners of Siberia that will cater to tourists who want to see a sky span­gled with stars. Some lovers of the night will trav­el to the moon, which has no atmos­phere to scat­ter arti­fi­cial light.

So take your pick: The daz­zling beau­ty of New York City from 30,000 feet or dark nights thick with stars? If I had to make a choice, I would choose the lat­ter. But the choice is not mine to make. It is a deci­sion the human race must make — unless we can fig­ure out some clever way to have it all.

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