The party started early on VJ Day. Though the official announcement that World War II ended wasn't made until closer to 7pm on Aug. 14, 1945, a scientific assessment of the famous photo of the couple kissing in celebration, called "VJ Day in Times Square" and widely known as "The Kiss," reveals the duo actually locked lips before then—at 5:51pm Eastern, to be precise.

So reports a team of scientists that includes a physicist and astronomer in the August issue of Sky & Telescope magazine. While they can't say with certainty who the couple is, they've used clues in the photo, such as shadows and light angles, as well as vintage maps and aerial photos, to determine the precise time photojournalist Alfred Eisenstaedt captured one of the century's most iconic images.

Physicist Donald Olson says it took four years to sort out, a journey that started in 2010 when an astrophysicist friend and colleague pointed out—in response to a New York Times article detailing new evidence about the image—that a peculiar shadow was draping part of the Bond clock in the background, reports Wired.

This isn't the first such mystery Olson has solved. He also figured out exactly when (and where) Van Gogh was when he painted "Moonrise" in 1889, as well as Claude Monet when he painted his first impressionist work, "Impression, Soleil Levant," in 1872.

Olson has even studied military mysteries and says that the USS Indianapolis was likely so vulnerable to a Japanese submarine in 1945 because it was backlit by a nearly full bright moon, reports the Los Angeles Times.

(This nurse claimed to be the woman in the photo.)

This article originally appeared on Newser: Physicist Unearths Key Detail About Iconic WWII Photo

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