While no one denies an iceberg sank the liner Titanic 100 year ago, there may have been another culprit that put it there, U.S. scientists say -- the moon.

Researchers at Texas State University say a once-in-a-lifetime celestial lineup of the sun, the Earth and the moon three months before the sinking may have created a record high tide that carried icebergs farther south into the Atlantic than anyone expected to see on the April 4, 1912, night of the sinking.

The researchers said the moon and sun had lined up in such a way their gravitational pulls enhanced each other, an effect well-known as a "spring tide." But the moon's perigee -- its nearest approach to Earth -- was the closest it had been in 1,400 years.

In addition, Earth's perihelion -- its closest approach to the sun -- happened just the day before, a truly rare combination of factors, they said.

"It was the closest approach of the moon to the Earth in more than 1,400 years, and this configuration maximized the moon's tide-raising forces on Earth's oceans," physicist Donald Olson said in a Texas State release Monday.

As Greenland icebergs travel southward, many become stuck in the shallow waters off the coasts of Labrador and Newfoundland and remain in place until they've melted enough to re-float or a high enough tide frees them, a process than can take several years, the researchers said.

But the unusually high tide in January 1912 caused by the rare cosmic alignment would have been enough to dislodge many of those icebergs and move them into southbound ocean currents, they said, where they would have just enough time to reach the shipping lanes for that fateful encounter with the doomed ship.

"The Titanic failed to slow down, even after having received several wireless messages warning of ice ahead," Olson said. "They went full speed into a region with icebergs -- that's really what sank the ship, but the lunar connection may explain how an unusually large number of icebergs got into the path of the Titanic."