Corrected entry: When the dying man kills himself by dropping the blow torch on the bugs, it causes a large explosion on the planet's surface which can be seen from space. The surviving man is shown afterwards with a burnt face and is acting a little wounded, but a fire that huge would burn him and his suit up like tissue paper, and if that didn't kill him, the blast would.
Corrected entry: After Carrie-Ann Moss extinguished the fire on the ship by depressurizing the whole ship everything that isn't attached to the ship had to be sucked into outer space with the atmosphere. But actually no solid parts are seen to be sucked out and when Moss has restored the artificial gravity lots of stuff is shown dropping. But why is this all still within the ship?
Corrected entry: When the crew arrives on Mars and run out of air-reserves, they are surprised to find out that Mars has a breathable atmosphere. Analysing the atmosphere of Mars is pretty easy to do, even with present technology, so it's inconceivable that a future space agency would send people down there without knowing that the atmosphere had changed (observing that conditions stayed the same on Mars was the very reason the mission went underway).
Corrected entry: Bowman resuscitates Gallagher after retrieving him from the lander in which he's escaped from Mars. She cuts through his suit and does several CPR pumps on his chest, and when he begins to respond, the ship's computer tells her "Stand him up, Commander." But during this scene they are in the ship's loading dock, floating in a zero-gravity condition. Without gravity, there is no up.
Corrected entry: When the 3 of them are caught in the middle of an ice storm while searching for the Russian ship, they wind up laying low for a while in the cold until the storm passes. Now if it's going to take 6 hours for the storm to pass and an ice storm that takes place at well below 0 degrees, how could they escape the storm with just frost on their hair and face? Even if it was above 0 degrees, the high winds would have given them full body frost bite or hypothermia.
Corrected entry: The crew makes a big deal about how all six of them are supposed to go down to the planet together. However, when the astronauts are being sent from the main ship down to Mars in their landing pod, there are only 5 seats in the pod.
Corrected entry: When the girl who is on Mars 1 gets rid of the fire in the ship by opening the hatch, it shows her being pulled out of the ship, as she would. Then, when the fire is all gone, it shows her being lowered to the floor, but behind her, the hatch is still open - she should still be getting sucked out into space.