Here’s why the New York City sky turned bright blue last night

A huge blue light flashed brightly over over the New York City skyline late Thursday night. New Yorkers filled social media with photos and videos of the phenomenon, which appeared to be centered over the borough of Queens. In short, people freaked out.

Con Edison quickly put everyone’s alien-conspiracy theories to bed. The utility company tweeted that what New Yorkers were seeing was the effect of a brief electrical fire that broke out at a substation in the Astoria neighborhood of Queens.

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ConEd's explanation made sense, but questions remained. For starters, why was the light so big and blue? In a phone conversation with a Con Edison spokesperson, Mashable got to the bottom of what happened, which was initially reported to be a transformer explosion.

“The failure was on a piece of equipment that monitors voltage, not a transformer explosion,” explained a Con Edison spokesman. “The failure caused a transmission dip so some people may have noticed their lights or TV flicker or go out. The grid is all interconnected. Anyone in New York City and possibly even Westchester County could have noticed an impact.”

And the bright blue light?

“There are failures of substation equipment that could result in an arc flash,” the spokesman said. “The failure results in the release of heat and light. The light is what folks saw last night.”

An arc flash occurs when an electric current flows through the air in between conductors. This flash of light was what New Yorkers saw in the sky. Con Edison also tweeted a more accurate summary of last night’s events in a tweet on Friday.

The Con Edison spokesman added that the light phenomenon on Thursday night lasted for approximately 10 minutes. The blue tinted light may have been intensified due to the cloud cover over the New York City sky last night, some reports postulated.

“This sort of thing doesn’t happen all the time,” said the spokesperson. “But there was one that also got considerable attention during Hurricane Sandy.”

So definitely not aliens. But "arc flash" lets you tick at least one term off your sci-fi checklist.