The special effects, combined with stock footage of natural disasters, make this a convincing "end of the world" movie.
In England, tabloid reporters come across the information that the Americans testing a nuclear bomb have knocked the Earth 11 degrees out of its orbit, sending it closer to the sun. Within a month the planet will be uninhabitable unless they do something drastic-set off another explosion to hopefully knock it back on course. Much of the story involves hard drinking, hard living reporter Leo McKern (Bill McGuire) and his love interest, Janet Munro (Jeannie Craig). If this movie was made today--with the same dialogue--it would be a study in sexual harassment, though these women from the 60's seem to take it all in stride. One of the more straight-forward, realistic disaster movies I have seen, up there with the Irwin Allen epics of the 70's.