Did Da Vinci Create a Second Mona Lisa? 

Leonardo Da Vinci’s Mona Lisa might be the world’s most recognizable painting, but a group in Zurich claims it isn’t really one of a kind. The Mona Lisa Foundation is unveiling what it claims is a sister portrait painted 10 years earlier by Da Vinci.

Sneak peeks reveal a similar figure with a slightly more pronounced smile. Its colors are also brighter than the famed Mona Lisa at the Louvre because it’s painted on canvas rather than wood. An art historian at the Mona Lisa Foundation says the painting has passed all mathematical and regression tests, adding that “all of the elements of the two bodies—the two people, the two sitters—are in exactly the same place.”

At least one expert on Da Vinci has already expressed skepticism at the foundation’s claims, saying it failed to recognize the subtleties of the original masterpiece. But he also acknowledged that scientific tests can’t rule out the possibility that it’s authentic. So as with the Mona Lisa’s famously elusive expression, this is a mystery that won’t be solved anytime soon.