Some legends are so powerful they must be debunked many times.

So it is that this month's issue of National Geographic magazine contains an article strongly suggesting that famed Arctic explorer Robert E. Peary, knowing that he had failed, faked his 1909 claim to have reached the North Pole.

The Geographic's is not the first attempt to set the record straight on what some consider one of the 20th century's biggest scientific or geographical frauds. Nor did the article contain significant new evidence in the controversy that began as soon as Peary lodged his claim on the front page of The New York Times, which had bought exclusive rights to his story.

Within days of his announcement, there were major efforts to discredit Peary's claim. Further challenges emerged in a congressional investigation of Peary in 1910-11. Since then, scores of articles, lectures, books and even a 1984 network television "docudrama" have sought to debunk Peary.

What makes the Geographic article noteworthy is that the National Geographic Society, which publishes the magazine, had long enjoyed a close association with the explorer. The society was a financial backer of Peary. And when the early controversy threatened to undermine both Peary's credibility and that of the society, it convened a blue-ribbon panel to endorse the explorer.

That step helped persuade Congress to rule in Peary's favor by passing a bill declaring him the official attainer of the North Pole, promoting him to rear admiral and granting him a lifetime pension.

As recently as January -- the start of the magazine's celebration of its centennial year -- National Geographic reaffirmed its historic ties to Peary by putting his portrait on the cover.

In a personal note in the September issue, Wilbur E. Garrett, editor of the Geographic, said the issue is "devoted to a once-in-a-century bit of introspection . . . holding up the mirror to ourselves for a change. We look not just at what's old but also at what's new about our past."

Historians and others familiar with the Peary controversy are surprised by the Geographic's change of heart.

"I am absolutely mystified as to what came over the National Geographic to make them change course," said George Michanowsky, a historian of exploration and a former director of the Explorers Club, of which Peary was the third president. "Peary and the Geographic have been so closely identified for all these years. You might even say they helped create him."

Not so much mystified as miffed is Dennis Rawlins, who in 1973 published a detailed book attacking Peary's claim: "Peary at the North Pole: Fact or Fiction?" Rawlins, an astronomer and historian, covered the old ground and discovered new evidence. Even before that, in 1970, Rawlins published all the main points of his case against Peary in the Proceedings of the U.S. Naval Institute.

A comparison shows that all of the Geographic's key lines of evidence against Peary were published in the book. Rawlins, whose book depicts the National Geographic Society as a collaborator in perpetuating the Peary fraud, is not cited in the article. Nor are any of the other examinations of the controversy.

The Geographic article concluding that Peary probably missed the pole and ended up 30 to 80 miles to the left is presented as if it were the first to raise a doubt about Peary:

"Through 75 years the sole records upon which Peary based his claim," an editor's note said, "have kept their silence, locked away from public scrutiny." Recently, the note went on, the Peary family released the records, which were held at the National Archives, and the magazine asked Wally Herbert, a veteran polar explorer, to examine them.

Herbert, a Briton who has spent more time in the Arctic than Peary did and who crossed it from Alaska to Norway by way of the pole in 1969, wrote that when he looked at Peary's diary of the trip he found major gaps. Herbert wrote he was "shocked by these revelations."

Neither the Geographic nor Herbert noted that the evidence of the diaries was introduced during the congressional hearings of 1910 and 1911 and that they have figured in every serious examination of the controversy since then, even though the diaries were locked away in the archives.

"Herbert's evidence is not original," Michanowsky said. "I haven't read a single line I didn't know before. Rawlins had it in the 1970s. And much of that was well known for a long time before that."

Garrett said in an interview that the magazine was not claiming Herbert had major new findings. "Nothing is new," Garrett said. "It's just that it's never all been put together in one place before. Slowly, we're trying to clean up old wives' tales that don't hold water."

Garrett said the Geographic decided to reexamine the Peary controversy in 1984 when CBS broadcast a fictionalized account of a dispute between Peary and a rival explorer, Frederick Cook, as to who had reached the pole first. Cook claimed on Sept. 1, 1909, to have reached the pole the previous year. Six days later, The New York Times published Peary's claim that he had reached the pole on April 6, 1909.

It was an age of ferocious competition among newspapers; while The Times backed Peary, the New York Herald backed Cook. Neither offered much evidence to support his claim. And each insisted the other was lying. In fact, most legitimate Arctic explorers doubted Cook, who had a reputation for making false claims, and sided with Peary, whose previous "farthest north" expeditions were well known and, in contrast to his North Pole claim, well documented.

The CBS broadcast took Cook's side, casting Richard Chamberlain as a kindly, sympathetic Cook and Rod Steiger as a brooding and unscrupulous Peary.

"When that came out," said Joseph Judge, senior associate editor of the Geographic who was in charge of the Peary project, "we thought it would be a good idea if the Peary family would release the diaries and let us do an honest evaluation, try to answer the question."

Judge said the family agreed and the magazine asked Herbert to review the diaries and try to determine what really happened.

Herbert said he was familiar with Rawlins' publications and that he had "studied them very thoroughly" when researching his article. "Basically, what Rawlins is saying is correct. Among all the books that have been done on this, I rate Rawlins extremely well. It's among the best. The main difference between me and Rawlins is that he is strictly a theorist and I'm speaking from practical experience. I've been to the Pole, and he hasn't."

Herbert said he borrowed nothing from prior investigators, preferring to start from scratch. "I think it was a turning point for the {National Geographic} Society," said Herbert, who was already on record as a Peary skeptic. "It was a bold move. They didn't know where I would come out on this."

Both Herbert and Rawlins note that Peary's account of his trek to the pole strongly suggests he was vulnerable to several navigational errors, any one of which would have pushed him miles to the left of the beeline northward track over hundreds of miles of drifting, rough pack ice that Peary claimed he followed.

On a previous expedition, Peary's records show he was 30 miles to the left of where he wanted to be after traveling only 100 miles. On the supposedly successful 1909 trip, Peary claimed that after traveling more than 400 miles, he was only four miles off course. Yet for this trip, Peary's navigational records show he was less exacting than before.

Rawlins and Herbert also cite the statements of Matthew Henson, Peary's longtime close colleague on explorations, that Peary behaved very strangely once they reached their farthest north point. Despite Henson's guess that they were at the pole, Peary refused to say.

On previous tries, Peary had taken care that his companions validated the sextant readings that showed their latitude. But this time, no other witnesses to the act of acquiring the crucial evidence were sought.

Perhaps the most damaging evidence is Peary's diary. Since the congressional hearings it has been known that the pages covering the time Peary claimed to have been at the pole are blank. Instead there are loose pages inserted, including one that proclaims, "The Pole at last!!!" The diary's cover is marked "Roosevelt {Peary's ship, anchored at the edge of the ice pack} to {blank} & return, Feb. 22 to Apr. 27, 1909." Why, investigators have wondered for 75 years, did Peary leave blank the space where he should have entered his farthest north point?

Although Herbert devotes much of his article to Peary's character, including his powerful belief that it was his destiny and his right to be the first to reach the pole, Herbert glossed over a more damning fact.

Two years before he claimed the pole, Rawlins said in his book, Peary made a fraudulent claim to have discovered what might have been the northernmost land on Earth.

Peary even named it Crocker Land, for George Crocker, the Southern Pacific Railway magnate who had donated $50,000 to his explorations.

Curiously, Rawlins noted, Peary made the first Crocker Land claim not in his report of the expedition in which he said it happened, but a year later -- shortly after Crocker made his donation -- and while writing his 1907 book "Nearest the Pole," supposedly an accurate narrative of his failed 1905-1906 try for the North Pole.

Rawlins found, however, that twice during the expedition in which he, as Rawlins puts it, "later discovered that he had discovered Crocker Land," Peary wrote that there was no possibility of new land being found north of Canada. Also, in "cairn records" which Peary placed in rock cairns along his land routes, there is no hint of what would have been a major discovery even on the record made and placed in the cairn the very day Peary later said he made the discovery.

Far from proclaiming any new discovery for that expedition, Peary wrote in his diary "to think that I have failed once more." On his next try for the pole, Peary was determined not to fail or, at least, not to be seen as a failure.