Setting sail 75 years to the day Amelia Earhart and her navigator Fred Noonan disappeared over the South Pacific, and returning three weeks later on Earhart's 115th birthday, members of The International Group for Historic Aircraft Recovery had hoped to bring back an answer to one of the 20th century's most enduring mysteries.

Unfortunately, the group was unable to conclusively prove its theory that Earhart and Noonan ended up on Nikumaroro Island (previously known as Gardner's Island) instead of their intended destination, Howland Island.

"As is usually the case with field work, we're coming home with more questions than answers," read a statement on TIGHAR's website. "We are, of course, disappointed that we did not make a dramatic and conclusive discovery, but we are undaunted in our commitment to keep searching out and assembling the pieces of the Earhart puzzle."

TIGHAR launched its ninth expedition on July 3rd after spotting what appeared to be landing gear from Earhart's Lockheed Electra in a photo of Nikumaroro Island taken three months after Earhart and Noonan's last made contact. They were further bolstered by a study that linked dismissed radio transmissions to Earhart's plane.

Despite the disappointing conclusion, the group remains undaunted.

"We have volumes of sonar data and many hours of high-definition video to review and analyze before we will know whether we found it," their statement continued. "Due to the limitations of the technology, we were only able to see standard-definition video images during actual search operations. Now that we're examining the recorded high-definition video, we're already seeing objects we want our forensic imaging specialist, Jeff Glickman, to look at. We'll also be getting expert second opinions on our best sonar targets."

[photo via AP]