This summer, the Explorer who discovered the Titanic shipwreck went in search of Amelia Earhart’s missing plane. Two weeks and a multimillion-dollar search later, Robert Ballard said he found no hint of it, according to The New York Times. 

Earhart and her Navigator Fred Noonan disappeared over the Pacific 82 years ago – on a journey that would make Earhart the first female Aviator to circumnavigate the globe. Her disappearance has led to numerous search efforts and spawned several conspiracy theories, but no one has been able to find conclusive evidence of where she might have gone.

One theory promoted by the nonprofit international historic aircraft restoration group (TIGHAR)is that its aircraft, a Lockheed Model 10 Electra, crashed into the coral reefs of Nikumaroro, a tiny Atoll that is part of the Phoenix Islands in the South Pacific. According to this theory, Earhart probably survived the crash and lived for some time on a desert island.

Related: Photos: the Incredible life and times of Amelia Earhart

Ballard first became interested in Nikumaroro after seeing a photograph, known as The Bevington image, taken on the island by a British officer in 1940. In addition, photos showed an object similar to the chassis from Electra, according to the Times.

In August, Ballard and his crew embarked on their research vessel, the Nautilus, to explore In and around Nikumaroro. The trip was funded by National Geographic Partners and the National geographic society, which is releasing a documentary about Earhart, including footage from the expedition on Sunday (October 20). 

The team mapped the island with sonar and a floating surface vehicle – and they used remotely operated vehicles to explore the deeper crevices of the seamount, of which Nikumaroro is a part. The team even searched 4 nautical miles and came up with nothing remotely related to Earhart. They did, however, find a bunch of rocks that were the same size and shape as the supposed chassis from the photo, according to the Times.

It “doesn’t surprise me at all that they haven’t found anything,” said Richard Gillespie, founder of TIGHAR. The electra was a delicate aircraft that was likely destroyed and “reduced to pieces of aluminum” by the surf after the crash, he said. “It’s been 82 years and these little pieces have been scattered and grown over (or) possibly buried s in underwater landslides.”

That doesn’t change all the evidence that “this is where it happened, this is where Earhart ended up,” Gillespie said. First, Earhart was issuing distress signals around these Islands, according to a 2018 TIGHAR report that was not reviewed. Gillespie adds that he wants to review Ballard’s data because “it’s possible that he found more than he thought he found,” he told Live Science. “Things can look like nothing and turn out to be something important.”

There are few inconclusive clues that point to this island as the place where Earhart and Noonan crashed, “primarily bones,” said Richard Jantz, Professor Emeritus of anthropology at the University of Tennessee, who was not part of the new Expedition. In 1940, some bones were found on the island and analyzed at the time by a medical examiner who claimed they belonged to a man.

The bones have since been lost, but TIGHAR found a doctor’s analysis of the bones. Jantz analyzed that lost report in a study published last year in the journal Forensic anthropology and concluded that Earhart bones were very similar to those found on Nikumaroro – more similar than 99% of the reference sample. 

Last year, a set of human bones matching the size of lost bones was found at a Museum on Tarawa island, and a team of researchers from the University of South Florida plans to conduct DNA testing on them to see if they could belong to Earhart, according to CNN.

“Nikumaroro is currently the only hypothesis that has real evidence to support it,” Jantz said. But a correct scientific hypothesis can be proven wrong – and one way to do that is to find more conclusive evidence that it disappeared elsewhere, he said. 

Ballard and his team’s return to Nikumaroro will depend on whether national Geographic archaeologists, who are now conducting DNA analysis of soil samples found at a makeshift camp on the island, find any evidence that Earhart was there, according to the times. 

But the team remains hopeful that they will eventually find the plane – and may explore an alternative theory that it crashed closer to Howland island, which was Earhart’s next scheduled refueling location before it disappeared, according to the Times.

“I was sorry to see Ballard come up empty-handed,” said Leo Murphy, a Professor of aviation science at Dayton College of aviation at Embry-riddle aeronautical University in Florida, who was also not part of the expedition. “It was unexpected with his previous successes.” 

But he hopes at least some part of her plane survived for researchers to find. “The key to any search is those big Pratt

Originally published on Live Science.

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