The mystery of what happened to Amelia Earhart has been a puzzle for decades.  Sonar footage has provided a possible answer.

The legendary fearless female American pilot has long been an iconic image for history buffs, and Earhart's 1937 disappearance only deepened the mystery. Theories have ranged from a plane crash or life as a castaway on an island to less-plausible ideas: capture and execution by the Japanese; getting eaten by cannibals; alien abduction.

Earhart's plane has now possibly been found via sonar footage on the Pacific island of Nikumaroro. A group of experts that have long been hunting for Earhart's plane took the footage.

The group, The International Group for Historic Aircraft Recovery (TIGHAR), pinpointed the island as the probable location of Earhart's plane crash more than  decade ago. Newly analyzed sonar footage taken during a 2012 visit bolster their theory.

The grainy photograph reveals a strange, dark shape about 600 feet below the water's surface - an "anomaly" that corresponds to the measurements of Earhart's plane.

The largest piece seen in the photograph is about 32 feet long; Earhart's plane was 38 feet 7 inches long. There's also another possible debris field nearby. The group theorizes that the plane crash-landed on reef flats but quickly washed into the sea.

"If our theory about what happened is correct, this is exactly what we would expect to see in just the place we would expect to see it," the group's leader told press.

Previous TIGHAR expiditions to the island turned up a jar of freckle cream from the 1930s, an American-made compact, and a flight jacket's buttons and zipper.

Now TIGHAR is hoping have the data analyzed further and take a trip back to the island, pending securing funding - last year's trip alone cost 2.2 million.  The analysis thus far looks like the target is "very promising".

The better a piece of evidence looks, the harder you have to try to disqualify it," TIGHAR writes. "So far, the harder we've looked at this anomaly, the better it looks. ... Maybe it's pure coincidence that it's the right size and shape to be the Electra wreckage - the Electra that so much other evidence suggests should be in that location."

Earhart, 39, and her navigator disappeared without a trace on July 2, 1937, while she attempted to become the first woman to fly around the world. During the journey's most dangerous leg, from Lae, New Guinea, to Howland, an island in the Pacific, Earhart lost radio contact and vanished.