It’s July 2, 1937. Clouds hang low in the sky. So does the Lockheed Electra 10E. America’s favorite female pilot, Amelia Earhart, flies the aircraft. She is supposed to be breaking a record by flying all the way around the world. Instead, she’s hovering over the Pacific Ocean—and maybe running out of fuel. A nearby Coast Guard ship receives Ms. Earhart’s last worried call. The pilot is never heard from again. She leaves history with a lasting mystery: What in the world happened to her?

A new study may finally help solve the puzzle. A researcher named Richard Jantz looks closely at old measurements of bones. The bones were found on Nikumaroro Island in the western Pacific Ocean in 1940. People have thought for a long time that the Electra may have crashed there. Are the bones Ms. Earhart’s? D.W. Hoodless, the doctor who studied the bones in 1940, said no. His study showed the bones belonged to a man. But Mr. Jantz looks at the bone measurements Dr. Hoodless took all those decades ago. He uses a computer program called Fordisc. The program can examine skeletal measurements. It guesses whether a person was a man or woman, what part of the world he or she came from, and how tall he or she was. Mr. Jantz also compares the measurements to clothes Amelia wore. He uses photos to guess the lengths of her arm bones. According to his study, the bones closely match Amelia Earhart.

There’s more evidence. People have searched Nikumaroro in the past. They have found a piece of a woman’s shoe, a box that would fit a navigation device, and a Benedictine bottle. (Benedictine is an herbal liqueur. Amelia Earhart was known to carry it.)

Mr. Jantz couldn’t study the Nikumaroro bones himself. They have disappeared. Without them, it’s hard to know if he’s really solved the Amelia Earhart mystery. But it does seem the evidence is starting to add up. It has taken more than 80 years!