For 67 years, the identity of the two kissers in one of America's most celebrated photos - the 'V-J-Day in Times Square' or simply 'The Kiss' - remained a complete mystery.

The photo was taken by Life Magazine photographer Alfred Eisenstaedt in Times Square, NYC on August 14, 1945 - a day that Americans will forever remember as the 'Victory over Japan Day' when Japan surrendered, putting an end to World War II.

In 2012, the book The Kissing Sailor: The Mystery Behind the Photo that Ended World War II identified that sailor as George Mendonsa and the nurse as Greta Friedman's.

Mendonsa and Friedman's story of how the iconic kiss happened was announced to the world, and the decades-long controversy was finally put to rest.

At least, until now.

The controversy has been blown wide open once again because Mendonsa and Friedman's supposed story could have never actually happened the way they tell it, according to Texas State physicist Donald Olsen and his two colleaguesphysicist Donald Olsen and his two colleagues: Russell Doescher, an astrophysicist at Texas State, and Steven D. Kawaler, an astrophysicist at Iowa State University.

The three scientists pointed out a fatal flaw in the story when they sought to answer another question about this iconic photo that few people think to ask: What time of day Eisenstaedt took the photo.

Olsen scrutinised the length and angle of the various shadows of people and buildings in the photo to help him get an idea of the time of day. He also built scale models of some of the buildings on Times Square back in 1945 based from measurements he found in old maps and blueprints of the square, as well as aerial photos to determine the time, once and for all.

LifeMagazineAlfred Eisenstaedt/Life Magazine

But what ultimately clinched it was the length of the shadow on a clock in the photo. The shadow, Olsen realised, was generated by a sign above the clock. By calculating the distance between the clock and sign, he determined the location of the sun in the sky, which then gave him the time of day.

After 4 years working on this project, Olsen and the team announced beyond any doubt that the famous kiss happened at 5:51 pm. According to Wired, you can read a report of their findings in the upcoming August issue of Sky and Telescope magazine.

The problem is that Mendonsa and Friedman's story place their kiss at around 2:00 pm. Mendonsa said that the kiss happened shortly after he left a movie at 1:05 pm and Friedman said that she was on a late lunch break.

Neither of their stories or reported times come even close to 5:51 pm.

Although he's solved the time of day, Olsen told Wired that he still hasn't a clue as to the identity of the people in the photo. That mystery is one that will have to remain unsolved, for now.

This article was originally published by Business Insider.

More from Business Insider: