泰坦尼克号沉没新说 或因海市蜃楼

After an entire century that included two high-profile government investigations and countless books and movies, we're still debating what really caused the Titanic to hit an iceberg and sink on that crystal-clear chilly night.

Maybe there's more to blame than human folly and hubris. Maybe we can fault freak atmospheric conditions that caused a mirage or an even rarer astronomical event that sent icebergs into shipping lanes. Those are two of the newer theories being proposed by a Titanic author and a team of astronomers.

New theories and research are important "but at its most basic what happened is they failed to heed warnings and they hit the iceberg because they were going too fast," said James Delgado, director of maritime heritage at the National Oceanic and Atmospheric Administration.

One of the novel new theories says Titanic could have been the victim of a mirage that is similar to what people see in the desert. It's the brainchild of Tim Maltin, a historian who has written three books about Titanic.

The unusually cold sea air caused light to bend abnormally downward, Maltin said. The Titanic's first officer, William McMaster Murdoch, saw what he described as a "haze on the horizon, and that iceberg came right out of the haze," Maltin said, quoting from the surviving second officer's testimony.

Other ships, including those rescuing survivors, reported similar strange visuals and had trouble navigating around the icebergs, he said.

British meteorologists later monitored the site for those freaky thermal inversions and said 60 percent of the time they checked, the inversions were present, Maltin said.

The same inversions could have made the Titanic's rescue rockets appear lower in the sky, giving a rescue ship the impression that the Titanic was smaller and farther away, Maltin said.

Physicists Donald Olson and Russell Doescher at Texas State University have another theory in Sky &Telescope magazine that fits nicely with Maltin's. Olson — who often comes up with astronomical quirks linked to historical events — said that a few months earlier, the moon, sun and Earth lined up in a way that added extra pull on Earth's tides. The Earth was closer to the moon than it had been in 1,400 years.

The unusual tides caused glaciers to calve icebergs off Greenland. Those southbound icebergs got stuck near Labrador and Newfoundland but then slowly moved south again, floating into the shipping currents just in time to greet the Titanic, the astronomers theorized. Maltin said the icebergs also added a snaking river of super-cold water that magnified the mirage effect.