On April 6, 1909, American explorer Robert Peary claimed to be the first man to reach the North Pole. Many have disputed the claim, saying his journey to the top of the world across the frozen Arctic sea couldn't have been made in the time he reported.
Nearly a century later, a young British explorer named Tom Avery had just finished a record-breaking journey to the South Pole when he began to learn about Robert Peary's controversial 1909 expedition.
"The more I read about it, the more I was struck by just the controversy up there. We still didn't really know who was the first guy to get to the North Pole," says Avery.
The controversy surrounding Peary's expedition centers on the explorer's claim that he and his team - an African-American assistant named Matthew Henson and four native Inuit guides - were able to travel from Ellesmere Island off the Greenland coast to the geographic North Pole in just 37 days.
Peary's team included no navigational experts, and the diary and photographic data Peary brought back from the pole don't provide conclusive proof that he actually reached it.
Avery says he felt a powerful need to settle the matter.
"It struck me that this was a fantastic opportunity to recreate Peary and Henson's journey and just find out how they did it. I wanted to find out the truth, and it seemed the best way to do that was to recreate their trip," he says.
Avery and his team follow Peary's footsteps
Avery and his team decided to retrace Peary's historic journey using the same techniques and equipment - including dog sleds - that the American explorer had used in 1909.
Avery says he figured that if he and his team could travel the same route, use the same breed of dog that Peary's team did and build replica sleds based on their designs, it would go a long way to finding out the answer.
Avery and his team of four people and 16 sled dogs set out on what Avery knew would be an arduous and dangerous journey to a forbidding wilderness. Avery says the North Pole is a living, breathing thing.
"The Arctic Ocean, it moves around with the currents. You have these enormous [ice] ridges that form before your very eyes. It [the ice sheet] splits apart, so you have open water to deal with, freezing cold temperatures, because you want to travel in the winter when it's held in frigid suspension, so minus 40, minus 50 degrees [Celsius] is very much the norm up there," he says.
After completing the 800-kilometer journey to the North Pole in record time, Avery says the team felt a mix of emotions about their extraordinary accomplishment.
"We were just relieved that it was all over, that we had survived, and that somehow against all the odds, we had beaten Peary's and Henson's time," says Avery.
It wasn't until they had returned home to Britain that "it really began to sink in just what we had achieved up there."
Avery has no doubt Peary was first to reach pole
After undertaking what he calls "the toughest expedition of his life," Avery is "more convinced now than ever" that Peary, Henson and their Inuit guides were the first men to reach the pole.
"Not only the fact that we beat their time, but we got a real insight into how they navigated and how they traveled, and with the equipment that they had, I had no doubt at all that they reached the pole."
That belief is shared by Robert Peary's grandson, Ed Stafford. He says Avery's journey should settle, once and for all, any lingering doubts about his grandfather's historic expedition.
"For me, it's just a further confirmation of what he said he did. There have been five complete full-scale investigations of his expeditions, and every single one in the end comes out [concludes] that, "Yup [yes], Peary did exactly what he said he did.'"
Another strong advocate for Robert Peary's place in history is Gilbert Grosvenor, the chairman of the board and past president of the National Geographic Society, one of the world's largest nonprofit scientific and educational organizations. Grosvenor says the society was a major backer of Peary's expeditions.
"Peary's critics always claimed it was impossible to dash to the pole in the time that Peary did it," Grosvenor says. "Well, Tom Avery proved that you could do that. He beat his time… and that takes away a little bit of the argument that Peary didn't make it."
Grosvenor believes Peary's polar expeditions inspired a zest for scientific discovery and paved the way for a century of exploration.
"For several generations now, explorers have looked to him as enthusiasm, as motivation to go out and to do things," he says.
The Guinness Book of World Records credits Avery and his team with what it calls the "fastest surface journey to the North Pole." But for Avery, that 2005 expedition was much more than a quick trip.
"The North Pole is often called the 'horizontal Everest,' and it's without doubt the toughest expedition of my life, and I think it would be very hard to beat, and particularly the whole reenactment of Peary and Henson's expedition. It was such a unique challenge, and we will look back on that travel with great affection for the rest of our lives."
Avery's historic trek to the North Pole is chronicled in his new book, To the End of the Earth.