Continuity mistake: Right after Matt Damon wakes up from the storm, while he goes back to the base, his costume has a small backpack with a "2" written on it. After he closes the second door the scene cuts and the backpack is gone. (00:12:25)
Continuity mistake: This mistake is in the extended edition: When Watney decides "I'm not going to die here", he packs up his five crew mates' belongings in plastic boxes and stows them in one of the two bottom bunk beds, from which the mattress has been removed. Then Watney is shown struggling out of bed, presumably the next morning, and a wide shot shows all six bunks. Every bed has a mattress and bedding on it and there are no boxes in sight. (00:19:10 - 00:19:50)
Continuity mistake: Mark Watney is shown whittling the cross when he needs something to ignite to burn the hydrazine, the next shot the cross is intact. (00:26:18)
Suggested correction: It is possible Martinez brought more than one cross and the one Mark is holding while lying down isn't the one he was whittling just before.
Continuity mistake: When Watney decides to retrieve Pathfinder, the date is sol 79. On earth Vincent says Watney has been traveling in the same direction for 13 days, and maps Watney's position as about one quarter of the way to his target. However Watney's helmet readout shows him arriving on Sol 94, only 14 days after he probably left the hab on sol 80. (00:42:00 - 00:44:00)
Continuity mistake: After breaking his helmet (with the "2" on the right side camera and with the name "Watney" on the back, he replaces it with one with no name and no number on the camera. However during the scene when he is preparing for the final trip, in shots of him manhandling solar arrays he has his old helmet on again. (01:34:25)
Continuity mistake: When he signs his name on the white sheet, his last day at the hab, he signs 'Watney' and underlines the name with the tail of the 'y'. Next shot where he walks away from that sheet, it's just a scribble signature.
Continuity mistake: When Vincent Kapoor is talking about getting Congress to fund a sixth Aeries mission, he states Aeries 3 evacuated after 18 SOLs. Near the beginning of the movie, after Mark Watney regains consciousness and returns to the HAB, you see Rover 2 parked behind the HAB with the crew cab facing away from the HAB. Later when Mindy Parks is comparing the SOL 18 and SOL 54 pictures, Rover 2, in the SOL 18 picture, is turned 180° (with the crew cab facing toward the HAB) from what we saw when Mark returned to the HAB on SOL 18.
Continuity mistake: During the segment showing the rocket carrying supplies exploding, Teddy is shown in the background walking out of the control room. However in the next scene Teddy is standing with others in the control room.
Continuity mistake: When Bruce Ng is video calling Teddy Sanderson and Mitch Henderson to explain the modifications Watney will need to make to the Ares 4 MAV, there is a point in which the model MAV behind Bruce contains only a chair, all other chairs and the control console having been removed. Then, as Bruce and Mitch explain to Vincent that since Martinez will be remote-piloting the MAV, Watney doesn't need the controls, there is a shot of Bruce pulling several chairs and the control console out of the model.
Continuity mistake: After discovering he is stranded and injured, Watney walks inside the hab and takes off his helmet and hood. His hairstyle changes three times between shots in a matter of seconds.
Continuity mistake: In the shot where Matt Damon finally gets captured by his rescuer, he is face to face with the woman astronaut and when he smiles his upper teeth are Hollywood white. In earlier shots, his teeth were shown stained and nasty. Also, shots soon after the rescue "white upper teeth" shot again reveal stained teeth.
Continuity mistake: When Watney is putting duct tape on the plastic patch over the hole where the Hab airlock blew out, the first shot shows him outside the Hab putting the last strip in an evenly distributed set, from about the 10 o'clock position down to about the 4 o'clock position. Then (after a quick reverse shot from the interior), suddenly he is placing a new strip up from the 8 to 2 position, covering a spot that was already covered when he did the 10 to 4 strip, but which is now suddenly blank.
Continuity mistake: After Matt Damon has had to ration his food, a double who is thin and emaciated and whose face is not shown is used to replace Damon in some shots. But Damon's real upper body, as muscular and big as ever, can still be seen in some other shots.
Continuity mistake: When he pulls the metal out of his stomach, the wound changes position slightly to the left and back to the right.
Continuity mistake: When Vincent draws the line on the Martian landscape picture and comes to the conclusion Mark is heading for Pathfinder, in the long shot, Mindy, who is standing next to Vincent, holds her left hand up by her face and her right arm down by her side. As Vincent begins to walk away, the camera instantly cuts to a close up of Mindy's face and now her right hand is up by her face and her left arm is down by her side.
Continuity mistake: Before planting the potatos he has to bring dirt into the HAB. The dirt on Mars is red due to high iron content. When we go to an inside view of the same dirt it's brown like here on earth.