by Simon Brew

In no small part due to the flak that George Lucas received for his never-ending desire to tinker with his Star Wars universe, most directors now resist the impulse to re-edit their films after they've been released. Even Steven Spielberg, who reworked parts of E.T. the Extra-Terrestrial for its 20th anniversary edition in 2002, ended up regretting it, and has since reversed his changes.

Still, the opportunity—and temptation—to go in and change just a little detail here and there, if needed, is always present. Which is exactly what writer/director James Cameron did with his Oscar-winning mega-hit, Titanic.

Originally released in 1997, the film is a testament to Cameron's renowned perfectionism, from beginning to end. Which explains why he felt compelled to act after receiving a "snarky" email about the movie from rockstar astrophysicist Neil deGrasse Tyson.

In his note, deGrasse Tyson explained that the star field Cameron created for one of the film's climactic scenes was all wrong.

“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," Cameron explained. “And with my reputation as a perfectionist, I should have known that and I should have put the right star field in."

Cameron wasted no time in responding: “I said ‘All right, send me the right stars for that exact time and I’ll put it in the movie.'" DeGrasse Tyson did exactly that.

As such, when Titanic was re-released in 3-D back in 2012, Cameron used the film's 15th anniversary as an excuse to make one tiny change to the movie: he redesigned the previously incorrect star map exactly to deGrasse Tyson's specifications, which is the version you'll see on all new copies released since then. (Not that you likely noticed.)