The fate of "America's Favorite Missing Person," pilot Amelia Earhart, may still be uncovered more than 85 years after her disappearance.

On a piece of wreckage that divers found off the Pacific island of Nikumaroro, scientists at Pennsylvania State University have now discovered a code of numbers and letters that may be assigned to the aviation pioneer's Lockheed Electra.

The International Organization for the Salvage of Historic Aircraft (TIGHAR) had put forward the thesis years ago that Earhart had made an emergency landing on a reef off Nikumaroro in the summer of 1937 and had lived on the uninhabited Kiribati Atoll for a few more months.

The wreckage with the rivets typical of Earhart's aviators seemed to point in the right direction.

Although the metal plate was found more than 30 years ago, only now have Penn State radiologists and engineers been able to uncover the codes "D 24" and "XRO" and "335" or "385" on the rusty aluminum surface.

According to Daniel Beck, head of the university's Department of Radiation Research and Engineering, the research group used neutron radiography.

The procedure made it possible to search for tiny traces under the deposits on the wreckage.

It has not yet been possible to clarify whether the numbers and letters are, as suspected, markings of the aircraft manufacturer.

Earhart's disappearance continues to fascinate many Americans to this day.

Former First Lady, Secretary of State and Presidential candidate Hillary Clinton is also one of the pilot's admirers.

In an attempt to become the first woman to orbit the world, Earhart and her navigator Fred Noonan left Papua New Guinea in early July 1937 for the Pacific island of Howland, some 4,200 kilometers away.

The desperate radio messages that she sent out shortly before the planned landing were the thirty-nine-year-old's last sign of life.

The International Organization for the Recovery of Historic Aircraft suspects that Earhart and Noonan missed the island and landed on a reef off Nikumaroro about 600 kilometers away.

The more than 200 radio signals received in the days after the Electra disappeared were broadcast from land, according to TIGHAR flight safety experts.

Other researchers, however, assume that Earhart's plane crashed into the sea when it ran out of gas for an unexplained reason.

However, there is just as little clear evidence for the "crash-and-sink theory" as there is for the thesis of the emergency landing off Nikumaroro.