Goofs

Putnam's house in the desert has a fireplace on the inside but no chimney on the outside.

Besides not having a stone chimney on the exterior of Putnam's house, the interior sets are much more spacious, and complex than the small "crackerbox" exterior building could hold.

(at around 30 mins) Telephone lineman Frank Daylon is shown working up on a utility pole. However, the pole clearly is carrying only electrical power lines (and not telephone service). So not only is there no reason for him to be on that pole, but it's also not possible for him to hear strange noises over telephone lines that aren't present.

When George and Frank are driving down the road, there is an aerial view of them, and Frank is sitting in the passenger seat with his right arm resting on the truck's window frame. In the following closeup, George has his right arm positioned next to his body.

Perry, wearing a space cadet suit and helmet, opens the hatch over his face. The point of view quickly switches to Ellen and the open door, as Perry walks through the doorway, but now the hatch over Perry's face is closed.

The equatorial mount on Putnam's telescope is not aligned for Arizona's latitude, nor, judging by the Moon's shadows, the direction of north. (Equatorial mounts are used to facilitate counteracting the Earth's rotation.)

Artistic license and suspension of disbelief notwithstanding, there is a scientific oversight worth noting: the alien's POV is in 3D, in spite of the fact that it's a cyclops. The otherworldly visitor has one eyeball and one pupil; it's necessary to have at least two in order to perceive stereoscopic vision.

After the spaceship has crashed, when they look through the telescope to see the crash site the image is the correct way up but since this is an Alvin Clark refractor telescope, the image should be upside down.

(at around 50 mins) According to the tear-off calendar on the wall in the sheriff's office, the climactic day of the movie was "February 11 Saturday". February 11 was one of the actual days of filming in 1953; however, in that year, it fell on a Wednesday. Presumably, the set dresser used an old prop calendar for 1950.

When Putnam and Ellen land back at the airport in the helicopter, Putnam is holding his pipe in his mouth upside down (bowl facing down). Pipe smokers sometimes have the bowl upside down, especially when it's raining. They tamp the tobacco tightly, light it, and then turn it upside down to keep the rain out of the bowl. Some pipe smokers will have them inverted even when it's not raining, possibly as an affectation, or simply habit.

The rear-view mirror on Putnam's Ford convertible disappears and reappears several times.

This is a commonly used filming technique; the rear-view mirror is removed when filming though the windshield so as to allow a clearer view for the audience.

The shot of the alien craft flying away from the desert at the end is the same shot of it flying across the sky for its crash landing at the beginning. It has simply been flipped in processing to appear as though it's going back the other way.

This is not accurate; the ship's "fire and smoke" trail the direction of the spacecraft's travel. If it were simply the beginning shot flipped, the fire and smoke would precede the craft as it leaves the earth.

The narration at the beginning of the film says it is early spring, but the calendar on the wall of the sheriff's office reads February 11.

Many parts of Arizona experience "early spring" weather in February; it can be assumed the narrator was not referring to astronomical seasons.

When the alien first goes walking about in the desert, the camera cuts to a startled owl, which tries to fly away only to be jerked back by the visible string tied to its leg.

John Putnam kneels and points out blood on a rock to Sheriff Warren. As he stands, he pushes on the rock and the rock indents.

The spider Putnam points out to the sheriff is evidently a toy tied to a string: it moves forward jerkily and without moving its legs.

When Putnam and Ellen blow out three candles, there's another half-second delay before the light in the room actually goes out. Clearly, the off-stage light, that was supposed to go out at the same time the candles were blown out, was turned off just a second too late.

When John turns around to go back and look for Frank and George, the tires on his car squeal while he's turning around on the sand beside the road. Car tires can't squeal on sand.

When John, Ellen, and Pete return to the airfield in the helicopter, they have a brief conversation with rotor noise in the background; yet neither the main rotor shaft (behind them) nor the tail rotor are moving.

Just after the crash when the spacecraft door is opening, you can see the silhouette of a stagehand can be seen pushing the door out of the way.

As the ship is coming toward the camera, there is what appears to be a post and a mirror at the left side of the screen just before it hits. This may be part of the equipment needed for the 3D effect.

The opening states that this is Sand Rock, Arizona. It is actually Victorville, California. All throughout the film there are Joshua Trees, which only exist in the Mohave Desert of California (where Victorville is). If it were in fact Arizona, particularly Southern Arizona, there would be Saguaro cacti, which only exist in the Sonoran Desert (which is Southern Arizona and Norther Mexico).

The stated temperature in the desert town of Sand Rock, AZ is 92 degrees, yet no one shows any reaction to the heat by rolling up their sleeves or sweating through their clothes. Instead of wearing lighter clothing, John Putnam sports a tweed suit throughout most of the film..

It is never explained how beings from another world know just where John Putnam lives, which Earthlings to kidnap, or where to find the items needed to repair the spaceship. When the alien duplicates confront Putnam, they state that they do not alter the minds or souls of the people they abduct.