At the beginning of the film, during the checkers game, the pieces are in different positions from different camera shots.
A character passes a magnet over what he calls "lead shavings," which collect on the magnet. Lead is non-ferrous and would not be attracted by a magnet.
Every time the ship in the ice is shown, it has it sails unfurled. Sailing ships furled their sails when not in use. As shown, the ship would have been dis-masted in the first serious storm.
The scientist suggests that "panspermia" explains that the organism got picked up from the atmosphere of one of the gas giant planets and carried to earth; that's not quite right, panspermia would be the theory that the organism got picked up from the atmosphere of one of the gas giant planets and carried to earth, and became the ancestor of all life on earth, which is obviously not the case in this movie.
The name of Dean Cain's character is _not_ a composite of characters from the Superman mythos. He is supposed to be a namesake descendant of the real-life Sir James Clark Ross, who accompanied his Uncle John and Admiral William Parry on that ill-fated nineteenth century Arctic expedition aboard the ships Fury and Hecla.
The first expedition is supposed to be in 1825. All of the weapons shown in use are from much later in the 19th and even 20th centuries.