"The problem with archaeology is that you can never say, almost never say, with 100 percent certainty," said Laurie LaBar, chief curator of history and decorative arts at the Maine State Museum.
A Norse coin found in Brooklin in 1957 has been puzzling scientists for decades. Analysis proves the item is legitimate. But how did it get here?
"There's a group of people out there who are very keen on believing that the Norse explored a lot of North America," said Bruce Bourque, former Maine State Museum chief archaeologist.
To learn more about the Vikings' impact in Maine, we head to the University of Maine to speak with a man named Hal Borns, a senior research scientist.
"There's been a long, long history of Vikings or Norse people occupying easternmost Maine," Borns said.
Borns is a geologist, but has been studying Norse influence in North America.
"Everyone's heard about viking explorations, people with horned helmets," said Borns. "It's a part of history that catches people's imagination."
According to Borns, people in easternmost Maine believe there were Vikings in the state. He says there's been no sufficient evidence to prove that, except perhaps the Norse coin.
"The Norse penny is part of, integral in that researching of that expansion," said Borns.
But the only known Viking archaeological site on this side of the world is in northern Newfoundland at a place called L'Anse aux Meadows.
"So that's it, so we have them there, no questions," Borns said.
So this site in Newfoundland proves the Vikings arrived in North America, but there's no concrete proof they made it any further. How did the coin make it here to the Maine coast?
The answer lies in the other items at the Goddard site. With no other Viking artifacts, scientists say it's unlikely the Norse had dropped the coin themselves.
"If they were here long enough to really do much of anything, you'd expect to find something, that was some other piece of viking material culture," said LaBar. "Somebody would have lost part of their knife."
Instead, they found a wide variety of stone objects from all over.
"We think that what was going on at this archaeological site was that it, we think it was a big trading center," LaBar said.
"The coin was probably also introduced to North America in that region, because we know that the Norse were actively trading," said Bourque.
Archaeologists say Norse merchants had been trading with Native Americans. Somehow, they say, the Viking coin fell into the mix.
"The coin has a hole and it was thought to have been worn perhaps by an Indian and it was a trade item with the existing colony at that point at L'Anse aux Meadows.
"It's a find brought by the Norse to North America which got out of Norse hands somehow and got involved in a Native trade network which is inevitable," said Bourque.
So the tiny Viking penny is a solid indication that the Norse were in North America, but not in Maine.
Does that mean the mystery is solved? Not entirely.
"In real science, nothing is ever solved," said Bourque.
"It's one of the long-standing mysteries. To a scientist, a mystery is a challenge, so that's what we're doing," said Borns.