Though James Cameron is a famous perfectionist who knows very well how much visual effects have improved since he made Titanic in 1997, he resisted the urge to tweak the film's effects when preparing it for a 3D re-release. So while the 3D conversion on the film is top-of-the-line and modern, some of the CGI-- the crowds milling on the deck, the steaming breath near the end-- may look kind of dated. It was all a deliberate effort on Cameron's part not to risk tweaking his movie to death, and he seemed all set to keep it exactly the way it was in the 90s… until Neil deGrasse Tyson came calling.
Tyson, the world-renowned astronomer, sent what Cameron calls a "snarky" e-mail pointing out that he'd botched the alignment of the stars glimpsed above the North Atlantic after the Titanic sank. Here's how Cameron said it himself to The Telegraph:
“Neil deGrasse Tyson 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, send me the right stars for that exact time and I’ll put it in the movie.’"
Obviously, this isn't a change that anyone other than an expert astronomer will notice-- which is why it's so delicious and wonderful that Cameron made the change anyway. As a mogul and a filmmaker with the unrivaled ability to do absolutely whatever he wants, Cameron can follow his every whim, and could very easily have used his famous temper to tell Tyson to fuck off. Instead, he bowed in respect to the scientist and made the change-- the only element of Titanic that will have changed at all. Compare this to how George Lucas has crammed the original Star Wars films with CGI and made the true original copies unavailable. Admire Cameron's restraint-- especially given that restraint is something you'd never, ever associate with James Cameron otherwise.
Here's a video of Tyson talking about the error if you want to see the nerdery happen before your eyes:
