Investigating Amelia Earhart's disappearance mystery with neutrons

2/1/2021

By Ashley J. WennersHerron

UNIVERSITY PARK, Pa. — It was 11-year-old Logan’s turn to choose a television show to watch with his dad, Daniel Beck, in October of 2020. Logan turned on the National Geographic channel, which was airing the 2019 documentary “Expedition Amelia.”

The film follows Robert Ballard, who discovered the Titanic wreckage, as he works to solve the disappearance of Amelia Earhart, who vanished during her attempt to fly around the world. Ballard does not find Amelia Earhart’s plane, but the documentary highlighted an aluminum panel that could offer clues — if only the technology existed to peer past decades of damage from rolling around the ocean floor.

“Passion accidentally met expertise,” said Beck, a pilot who also manages the engineering program for the Penn State Radiation Science and Engineering Center (RSEC), home to the Breazeale Nuclear Reactor. “The documentary ended with the idea that maybe, in the future, there will be technology to better examine the clues in Amelia Earhart’s disappearance, including this panel. And I realized that technology exists. I work with it every day.”

Beck emailed Richard “Ric” Gillespie, who leads The International Group for Historic Aircraft Recovery (TIGHAR) and was featured in the documentary. Gillespie and his wife, Pat Thrasher, founded the group in 1985 and have focused on Earhart’s disappearance since 1988. In his email, Beck explained how neutron technology might be able to elucidate more information from the panel that Gillespie found on the Pacific island Nikumaroro in 1991.

Gillespie returned his email less than 12 hours later.

“We address famous aviation mysteries with science in an attempt to solve them,” Gillespie said. “That’s what brought us to Penn State: applying science to the Amelia Earhart mystery.”

Gillespie found the metal panel in storm debris on Nikumaroro, a Pacific island about 300 miles away from Earhart’s actual destination of Howland Island during her 1937 attempt to be the first person to fly around the world at the equator. It is theorized that Earhart landed on the reef surrounding the uninhabited island, where a human skeleton was found in 1940. While the bones were lost, a 2018 study found that a historical record of the bones’ measurements matched Earhart’s measurements closer than 99% of the rest of the population. Recently, as described in the National Geographic documentary, a skull fragment that may be from the original skeleton was found in a storage facility in a museum on a nearby island. It is currently being tested to see if it genetically matches with any of Earhart’s relatives.

Beck knew they might be able to do equivalent work with the metal patch: examine it to determine what, if any, marks might reveal the history of this piece. Maybe they could unearth long-faded serial numbers or learn more about unexplained marks along the edges of the panel.

Beck brought the idea of examining the metal patch to Kenan Ünlü, director of RSEC and professor of nuclear engineering.

“Initially, I was a little skeptical,” Ünlü said. “We’ve had inquiries about these kinds of things before, but we had an extensive call with Ric, who was clear that they’re interested in whatever data we might be able to provide, even if it proves that the patch couldn’t possibly belong to Amelia Earhart’s plane. We agreed to see what we could see.”

Beck and Ünlü proposed using neutron radiography and neutron activation analysis to examine the external and internal makeup of the patch, respectively.

“We can use these techniques to look at the surface images and make a qualitative and quantitative determination of ingredients,” Ünlü said. “I didn’t think we’d see much because aluminum is opaque to neutrons and activation analysis reveals mostly aluminum. Since it had been in the sea, we thought maybe we’d see coral buildup, maybe some surface paint on the sample.”

Neutron radiography involves using neutron beams from the Breazeale Nuclear Reactor. A sample is set in front of the neutron beam, and a digital imaging plate is placed behind the sample. The neutron beam passes through the sample into the imaging plate, and an image is recorded and digitally scanned.

“As the beam passes through, if it were uniform density, we wouldn’t see anything,” Beck said. “If there’s paint or writing or a serial number, things that have been eroded so we can’t see with the naked eye, we can detect those.”

Neutrons can create a contrast with materials that contain carbon or hydrogen by either absorbing or scattering neutrons.

“The other approach, neutron activation analysis, helps precisely identify the make-up of material,” Ünlü said. “This approach can determine the ingredients of a materials at parts-per-million or parts-per-billion level sensitivity.”

The patch appears to have axe marks along the edges, according to Beck, except for one edge where the metal was repeatedly flexed until it snapped from whatever it was attached to.

“It doesn’t appear that this patch popped off on its own,” Beck said. “If it was chopped with an axe, we should see peaks for iron or nickel left by the axe along that edge. Neutron activation analysis gives us that detail at a very fine resolution.”

For example, from 2004 to 2012, Ünlü and his graduate students used the technique to measure concentrations of gold particles found in the dated rings of single tree that grew in Greece from 1411 to 1988. They matched gold spikes to volcanic events, which can cause major environmental impact thousands of miles away, to the exact year of the eruption.

“We’re not going to find Earhart’s signature on the patch or something that definitely confirms this belongs to her plane,” Beck said. “We will provide more data about what this patch is.”

From the first images, Beck and Ünlü said, it was clear they were uncovering new information. They are continuing to analyze the patch and likely will not reveal their findings until late spring of 2021, after more comprehensive experiments that include adjusting the irradiation time and power level of the reactor.

“What the Penn State team is learning about this artifact is beyond anything we’ve been able to do in 29 years of research,” Gillespie said. “It’s possible we’ll learn something that actually disqualifies this artifact from being part of Earhart’s plane, but I prefer the knowing! It is so exciting to work with scientists who share our passion for getting to the truth, whatever it is.”

 

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MEDIA CONTACT:

Megan Lakatos

mkl5024@psu.edu

INVESTIGATING AMELIA EARHART’S DISAPPEARANCE MYSTERY WITH NEUTRONS: Researchers at Penn State’s Breazeale Nuclear Reactor are using neutron radiography and neutron activation analysis to examine the external and internal makeup, respectively, of metal patch that may belong to Amelia Earhart’s lost airplane. VIDEO: PENN STATE COLLEGE OF ENGINEERING

“What the Penn State team is learning about this artifact is beyond anything we’ve been able to do in 29 years of research.”
—Richard “Ric” Gillespie, who leads The International Group for Historic Aircraft Recovery