The black-and-white picture of mushroom-shaped smoke billowing into the sky is synonymous for most with Aug. 6, 1945, the day the United States dropped the atomic bomb on Hiroshima, Japan. With President Barack Obama’s visit to the memorial Friday, the iconic image was once again conjured up in many people’s mind. But there’s a problem. The photo most people associate with the act of war is not actually a mushroom cloud, the New York Times wrote Monday in a piece titled “The Hiroshima Mushroom Cloud That Wasn’t."

While the photo was definitely of the A-bomb being dropped on Hiroshima, it’s not an image of a mushroom cloud, nuclear experts told the Times. It's ascending smoke from raging fire, said Richard L. Garwin, leading bomb designer and longstanding nuclear arms adviser for Washington, D.C.

The photo was taken by an American plane three hours after the bomb was dropped, John Coster-Mullen, an expert on the Hiroshima bomb, told the Times in an email. The smoke in the photo “is most definitely not the original mushroom cloud, which had long since dissipated.”

If the photo had truly captured the original mushroom cloud, it would have been much larger than what the American plane captured. A mushroom cloud can last for about an hour “before being dispersed by the winds,” according to “The Effects of Nuclear Weapons,” a federal guide. It takes nearly 10 minutes for a mushroom cloud to reach its maximum height.

A photo of the true mushroom cloud isn’t as dramatic, but it does exist. The image was taken, minutes after the atomic bomb was dropped, at a Japanese elementary school in Kaitaichi, which is part of present-day Kaita, the Atlantic wrote in 2013 about the rare picture. The town is located 6 miles east of Hiroshima's center.

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