The mystery of Amelia Earhart has tantalized for 86 years: Why it's taken so long to solve

Solving a mystery nearly nine decades old isn't as easy as connecting the dots, especially when those dots are tiny islands spread throughout the world's largest ocean.

A team of underwater archaeologists with Deep Sea Vision, using marine robots equipped with sonar imaging, believe they may have found the airplane belonging to Amelia Earhart, the famed aviator who, along with her navigator Fred Noonan, disappeared as they tried to circumnavigate the globe in 1937.

And while the world may be tantalizingly close to learning the fate of Earhart and Noonan 86 years after the pair's plane went down somewhere in the Pacific Ocean, there are significant challenges that remain, experts say.

First and foremost among them: The sheer size and depth of the Pacific.

"It's a huge area, and the problem is, the plane is really, really small," said Nicholas Makris, professor of mechanical and ocean engineering at Massachusetts Institute of Technology and an expert in ocean exploration.

"This is like looking for a needle in a haystack," he said. Earhart's Lockheed Electra 10-E had a wingspan of about 55 feet and was 38 feet long.

Compare that, Makris said, to one degree of latitude, which is 60 nautical miles. The Pacific Ocean is 135 degrees: "It's a monstrous area," and the plane, if it's even intact, would be minuscule. If it's not intact, finding its remains would be even more difficult.

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The breadth of the search area is one matter. The depth of the ocean where it's believed Earhart's plane went missing is another.

"It's lost in the darkness of the ocean," said Makris, whose specialty is undersea imaging and acoustics. "The sound (from sonar equipment) takes the darkness out, but it's so far down that, from the surface, it can look like a speck."

Autonomous underwater machines have to survey the ocean floor in what Makris described as "lawnmower patterns" to get a closer, more accurate glimpse of the possible wreckage.

Anthony Romeo, CEO of Deep Sea Vision and a former Air Force intelligence officer, recognized those challenges when he and his team set out to find Earhart's plane in early September.

"The remoteness of where she went down" was the biggest obstacle, he told USA TODAY. "There are not a lot of ports, not much equipment, not a lot of vessels in that area. If it went down in Lake Michigan, we'd have found it years ago."

"The Pacific Ocean is huge, which Amelia Earhart found out for herself" on her final, doomed flight, Romeo said. "It's an incredible distance to cover. We were out there for 100 days, over rough seas, and not a lot of ports to reprovision."

What's next for Deep Sea Vision and its discovery?

Romeo said the discovery of what looks like a plane at the bottom of the ocean is just the first step for his team. Next up: Confirming that what they found is a plane and that it's Earhart's.

"That's where we need different equipment so we can take a closer look, see how it's laying on the sand, and work with others who have an interest in this," Romeo said.

Asked whether that meant sending down a manned vessel, Romeo said that was unlikely: "We have no interest in doing that at the moment," he said, acknowledging the tragic deaths of five people on the Titan submersible in June 2023.

Bringing up the wreck − again, if it is a plane and if that plane is the one that belonged to Earhart – "would be a massive project that would probably take years," Romeo said.

Still, he wants Earhart's plane to ultimately find a home in the Smithsonian Institution.

The former pilot, and son of a longtime Pan Am pilot, Romeo called Earhart "a true American hero who came from humble beginnings to international celebrity."

"As long as she's still missing, there will be people trying to find her."

What other unsolved oceanic mysteries remain?

If Romeo's right, and he said he feels "pretty good about it," finding Earhart's plane is only one of a host of maritime mysteries.

In 2014, Malaysia Airlines Flight 370 and the 239 people on board disappeared on a trip from Kuala Lumpur to Beijing. Only a tailpiece from the plane has been found, off the coast of Mozambique. Romeo said he'd love to search for the plane, giving closure to families still desperate for answers.

In 1945, five bombers took off from Fort Lauderdale, Florida, on a routine three-hour training flight. Collectively called Flight 19, the bombers' lead pilot seemed to become disoriented, and the planes eventually flew so far off course they lost radio contact with their base, according to History.com. They were never found.

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There are still missing soldiers from the Vietnam War. In the war's earliest days, Flying Tiger Line Flight 739 was headed to Saigon when it, and all 107 people on board, disappeared before a stopover in the Philippines, according to Flying Magazine. The plane was never found, and adding to the families' anguish, those presumed dead have never been included among the official war dead (though a bill was introduced in Congress in 2021 to change that).