From NPR’s Picture Show: An old, washed-out photograph shows two men at the edge of a snowy abyss, clad in rudimentary mountaineering gear. Those men are George Mallory and Andrew Irvine, and the photo is the last known photo ever taken of them. It was snapped before they disappeared into the clouds of Mount Everest on June 8, 1924.

The British climbers were on a mission. They wanted to become the first people to stand atop the world’s tallest mountain — three decades before Sir Edmund Hillary made his landmark climb. But after they set out, no one knows exactly what happened to them.

Kent Moore might have found the answer…