In an interview in 2012, James Cameron was asked by
UK magazine Culture if he’d made any revisions to Titanic for its upcoming 3D rerelease.
Oh, there is one shot that I fixed. 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 bitch, 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.