Continuity mistake: After the aliens announce their intentions Dr. Marvin and the generals meet together back at the Pentagon office. Dr. Marvin's hanky in his jacket pocket is arranged differently between shots. (01:07:05)
Continuity mistake: At sky hook the soldiers pull up in a jeep and jump out carrying M1 carbines. In the next shot when they lay on the ground to fire at the aliens they are armed with M1 Garands.
Continuity mistake: The alien helmet that we see on the desk as the generals introduce themselves to Carol and Dr. Marvin is not the same one we saw earlier. This one has a large lip on the bottom and the one that he removed from the dead alien did not. (00:56:20 - 00:59:35)
Continuity mistake: The alien translating device from the helmet that Dr. Marvin places on the table is not the same one he was just holding. The shade, shape and shadow on the table all change between shots. (00:59:50)
Continuity mistake: Dr. Marvin and the others stop the car and watch the alien spaceship that shows up landing outside the Belmont lab. At first the car is parked on an angle then in the next close-up shot it's on level ground. (00:52:00)
Continuity mistake: Prof. Kanter is incinerated by the alien's beam and his cane falls down next to him. The next time we see his smoldering body the cane has been moved and is now touching a tree to the right of the screen. (00:55:05)
Continuity mistake: As the motorcycle cop gets his brain scanned by the aliens Infinitely Indexed Memory Bank the brain we see is the same one we saw when Gen. Hanley's got his brain scanned earlier in the movie. (00:24:25 - 00:43:10)
Continuity mistake: As they speak to the aliens inside the spacecraft look closely as the motorcycle cop draws his gun twice before he shoots at the aliens. (00:42:45)
Continuity mistake: Dr. Marvin says the batteries are dead on the tape recording that he makes, yet several shots later the lights behind Carol and he are back on. (00:25:50)
Continuity mistake: Maj. Huglin walks in as Dr. Marvin works on the high frequency ultrasonic gun and says, "Hello". Another engineer works to right of them and in the next shot he disappears. (00:47:40)
Continuity mistake: Maj. Huglin walks into the lab as Dr. Marvin works on the high frequency ultrasonic gun and all the equipment behind them is lit up. In the next shot it's not. (00:47:40)
Continuity mistake: Several authentic looking prop newspapers have headlines reading that "Operation Sky Hook has been wiped out" and they all have the same mistake, no date on top. (00:26:40)
Continuity mistake: Dr. Marvin tries out his high frequency ultrasonic gun in front of Maj. Huglin. Before he fires it the device is moving, than in the next shot it's still. (00:47:05)
Continuity mistake: Dr. Marvin tries out his new improved magnetic interference unit and an alien craft is spotted flying around inside of the Belmont lab above their heads. Before the craft takes a dip down at them they're standing on the right of Dr. Marvin's magnetic device, but when we see them again they're standing on the left of his device. (00:50:20)
Continuity mistake: As Dr. Marvin tries out his high frequency ultrasonic gun in front of Maj. Huglin they're all staring at it. In the next shot they're looking at the cement block before it's destroyed. (00:47:05)
Continuity mistake: Dr. Marvin walks in as Carol sleeps in their hotel room and then proceeds to call the aliens on his shortwave radio. By the time he walks out of the room to meet with them by the Chesapeake Bay the items on top of his dresser have moved, without anyone going near them. (00:31:10)
Continuity mistake: Dr. Marvin tries out the new improved magnetic interference unit and invites Prof. Kanter to be the first one to shoot it. He walks over to Prof. Kanter standing in front of the gun twice between shots. (00:49:30)
Continuity mistake: As Dr. Marvin tries out his high frequency ultrasonic gun in front of Maj. Huglin the engineer to the right of them turns on the generator. In the next shot the lighting has changed and the the shadow of Dr. Marvin's head appears on the pillar behind him. (00:47:00)
Continuity mistake: At the Pentagon Carol and Dr. Marvin speak to the generals and one of them holds a pipe in his right hand. In the next shot he's holding the pipe in both hands. (00:46:15)
Continuity mistake: Carol and Dr. Marvin are locked in the underground bunker at "Operation Sky Hook" as the power goes totally dead. Somehow in total darkness without any power we still hear the sound of the aliens speaking which is strange because if you look at the tape recorder it's not running at all. (00:24:40)
