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'Titanic' director tweaks the sky

Paramount Pictures / 20th Century Fox

Film director James Cameron talks with Leonardo DiCaprio and Kate Winslet during the shooting of a crucial post-sinking scene in "Titanic." The newly released 3-D version of the film will show the sky as it actually appeared that night, thanks to astronomer Neil deGrasse Tyson's goading.

Astrophysicist Neil deGrasse Tyson doesn't mind that "Titanic" film director James Cameron called him a "son of a bitch" for shaming him into correcting the movie's constellations.

"I take it as a frustrated expression of affection," Tyson, director of New York's Hayden Planetarium, told me today. "As in, 'you son of a bitch, you got me there.'"

Thanks to Tyson's persistence, moviegoers who go to "Titanic" in 3-D will see a truer representation of the night sky when Rose (played by Kate Winslet) looks up into the heavens after the ship sinks. "That sky, I would say, was the most important sky in the movie," Tyson said. And in the original 1997 version of the film, it was wrong.

In a widely quoted interview with the British magazine Culture, Cameron said the sky scene was the only shot he fixed for this year's 3-D re-release:

"It's because Neil deGrasse Tyson, who is one of the U.S.' leading astronomers, sent me quite a snarky email saying that, at that time of year, in that position in the Atlantic in 1912, when Rose is lying on the piece of driftwood and staring up at the stars, that is not the star field she would have seen, and with my reputation as a perfectionist, I should have known that and I should have put the right star field in.

"So I said, 'All right, you son of a b**ch, send me the right stars for the exact time, 4:20 a.m. on April 15, 1912, and I'll put it in the movie.' So that's the one shot that has been changed."

Rose (Kate Winslet) looks up at the stars in this scene from "Titanic."

The basic problem was that a space-savvy observer would see that the sky in the original version of the movie was unrecognizable, and in fact was produced by mirroring made-up stars on the left and right halves of the screen. Tyson saw that as a needlessly sloppy move, and he made that opinion known to Cameron and his team in a succession of letters, emails and personal encounters. He wrote about the "Titanic" trip-up and other Hollywood missteps in his 2007 book, "Death by Black Hole." You can watch him tell the tale about "Titanic" and other sci-fi movies in this video clip:

Neil deGrasse Tyson on inaccuracies in science-fiction movies and the "Titanic" night sky.

When Cameron's people finally asked Tyson to provide a better sky, the astrophysicist used a standard planetarium program to generate the star field for the proper latitude and time of night, captured a high-resolution image and sent it off to the filmmakers.

"The Big Dipper came out nicely," Tyson said.

The sky was initially fixed in the bonus materials for a special DVD version of "Titanic" a few years ago. "I took that as a triumph and let it be," Tyson told me. Now the corrected sky appears in the big-screen version of the film itself, thanks to post-production wizardry.

Tyson said he can understand why it took a big re-release for Cameron to change the sky. "As a director, you don't want to have to rethink all that, and I respect that," he said. Tyson said his respect for Cameron has grown even more now that the right stars will be on display in theaters around the world.

Will Cameron put the space-savvy S.O.B.'s name in the credits for the 3-D movie? Tyson says he doesn't know, and really doesn't care.

"If he does, that's fine," Tyson told me. "I'm a servant of the public interest and the public's appetite for information about the universe. I get these calls all the time. ... The mere fact that an artist cares about getting the science right, and thereby transmitting that science literacy to the consumers of that art — that's enough reward for me."

More about 'Titanic' and Neil deGrasse Tyson

Alan Boyle is msnbc.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter or adding Cosmic Log's Google+ page to your circle. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for other worlds.