Quando i mondi si scontrano

Screenwriter Bruce Joel Rubin saw this film as a ten-year-old, and has cited it as "the beginning of the emergence of philosophy" in his life. In The Dialogue: An Interview with Screenwriter Bruce Joel Rubin (2007), he explains that right after he and a boyhood friend saw the film, they spent hours discussing the end of the world. Rubin mentions this memory while explaining that Steven Spielberg approached him to do the screenplay for a remake of "When Worlds Collide," and that it eventually evolved into Deep Impact (1998), with Rubin credited as one of its two writers.

Throughout the film, Bellus is referred to as a star; this is presumably how life is able to be sustained on Zyra. However, if this was the case, Earth would have been destroyed from the heat long before Bellus collided with it, even if it was a small brown-dwarf star. Also, departure should have been at least 17 days earlier, before descending deep into Bellus' gravity well and needing far more fuel. This part of the plot, and the time to build the ship, could have been resolved by sticking to the novel's pair of planets and a longer time frame - Zyra and Bellus both passing by with Bellus, a gas giant planet, ripping up Earth's surface, then returning months later for Bellus' direct collision with Earth, as Zyra enters orbit around the sun.

Edited from Il falco del Nord (1938)