At 4:31 on the morning of January 17, 1994, the ground under the San Fernando Valley shifted, and for somewhere between ten and twenty seconds the Northridge earthquake threw Los Angeles out of its bed. When the shaking stopped, so did the city’s light. The magnitude 6.7 thrust had knocked out the Department of Water and Power’s entire system — the first time in the utility’s history that the whole city went dark at once. Streetlights, porch lights, billboards, parking-lot floods, and the entire orange dome of the city’s glow, all dead in the same instant.
Millions of people walked outside into that dark to check the damage and wait for the aftershocks. The moon was a thin crescent that had set hours earlier, and over much of the basin the sky was open. With nothing left burning over their heads, they looked up.
What they saw, a number of them decided, was worth calling someone about.
The sky that was always there
The thing overhead was the sky as it actually is. Not the dozen or so smudged stars that survive a normal Los Angeles night, but the full field — thousands of points of light, sharp and layered, and running through them a broad, pale, faintly luminous band stretching from one horizon to the other.
That band was the Milky Way. The flat disk of our own galaxy, a hundred billion stars or more seen edge-on, the thing every human ancestor for tens of thousands of years had slept under as a matter of course.
Most of the people standing in their driveways that morning had simply never seen it. They had been born into a city bright enough to erase it, and had lived their whole lives without once looking up at the galaxy they were inside. So when the lights failed and it appeared, it did not read as the night sky. It read as something new in the sky, and possibly something wrong.
The phones at Griffith
The calls that are firmly documented went to the Griffith Observatory, the white-domed building on the south slope of Mount Hollywood that had been answering the public’s sky questions since 1935. A second version of the story has circulated for years — that anxious residents also rang emergency lines to report a “giant, silvery cloud” hanging over the city, something that read less like weather than like a consequence, smoke or fallout or whatever it was the shaking had let loose. It is a better image than it is a fact. The detail appears in dark-sky advocacy retellings decades after the event, and no contemporaneous report or dispatch record has ever been produced to support it. What survives scrutiny is the quieter version: the people who wanted an explanation called the astronomers.
Edwin Krupp, the astronomer who has run the observatory since 1974, later put it plainly to the Los Angeles Times: “The stars were in fact so unfamiliar, they called us wondering what happened.” They were not reporting a comet or a UFO. They were reporting the ordinary night sky, because the ordinary night sky had been gone from their lives long enough to read as a hazard.
The earthquake had revealed it by accident, and only briefly. Crews had ninety-three percent of the utility’s customers back inside twenty-four hours — and neighborhood by neighborhood, as the lights returned, the galaxy vanished again behind the glow and the city went back to its dozen visible stars.
What the lights had erased
The thing the quake switched off has a name and a fairly precise measure. Light pollution — the scatter of artificial light upward into the atmosphere, where it bounces back down as a uniform glow — washes out everything fainter than the brightest stars and planets. Los Angeles produces enough of it that the city’s sky glow can be picked out from the summit of Mount Whitney, some two hundred miles away.
A 2016 survey of artificial sky brightness, built from satellite data and led by the Italian researcher Fabio Falchi, put numbers to how far this has gone. The Milky Way, it found, is now hidden from more than a third of humanity — from about sixty percent of Europeans and nearly eighty percent of North Americans. More than ninety-nine percent of Americans and Europeans live under a light-polluted sky of some kind. They live, as the residents of Los Angeles did, under a permanent dome of their own light, with the galaxy on the other side of it.
The fuller toll
Everything else about that morning was a catastrophe. The thrust fault that revealed the sky had killed dozens of people and injured thousands. Water mains had ruptured across the San Fernando Valley, dropping pressure to zero in places and leaving tens of thousands of customers without service for days. Freeway overpasses had folded onto the road below.
But for the length of one blackout, the same shock did something no policy or campaign has managed to do for a major American city since. It turned the lights off, all of them, at once — and the people who walked out under them looked up and saw, some of them with alarm, the sky that had been over their heads the entire time.