Complaints about the headline aside, it is the perfect sort of doomsday prophecy story. It is far enough away that the people who pulled it out of Newton's writing will be forgotten, its near enough that the reader could imagine being alive at that time and wondering what would happen. Erich von Däniken exploited this in his "Ancient Astronauts" stuff, predicting the Mayan's called it with a 2012 extinction event (whoops :-).

Since you only get one end of the world prophesy (when it passes you're a crackpot and everyone who believed you now hates you intensely) you need to pick it to land post retirement at least since you'll not have any credibility afterward. Predicting '2060' (and yes I know Newton wrote no earlier than) as the folks who have used Newton's works to date it, being a bit more than 40 years away will have all of these folks retired by then. My guess is they will really try to milk it for all it is worth in the 2040's.