Leonardo da Vinci's Mona Lisa

One of the many questions that have long circulated about Leonardo da Vinci’s Mona Lisa is why the figure is missing her eyebrows. While some researchers have suggested that it was common practice for wealthier women to pluck them clean in the artist’s time, a new study of the painting with a 240-megapixel camera suggests another answer: Leonardo actually did paint them there.

Pascal Cotte, who analyzed the painting with a camera that is so remarkably sensitive to light that it can see through layers of paint, says that Leonardo appears to have built up the foundational coats of paint for eyebrows. So where did they go? Cotte says restoration work over the past 500 years may have wiped the hair clean off the Mona Lisa’s forehead — or that a chemical reaction related to a special glaze that Leonardo used may be the culprit.

Losing your eyebrows can’t be much fun, though Cotte says that is the least of the changes the Mona Lisa has suffered. The somber, gray sky behind the sitter was originally blue, according to Cotte, and her skin was a crisp white, lacking the yellow tint it has today. What’s more, it seems that her face and notoriously enigmatic smile were much wider, though the years have stripped away the paint that portrayed that.

Results from Cotte’s study will be featured in an exhibition at the Museum of Science and Industry in Manchester called “The Secrets of the Mona Lisa.” The show, which opens tomorrow, will unfortunately not feature the work in question. She is snugly — and probably permanently — ensconced within the walls of Paris’s Louvre, trying to avoid any further alterations.