Continuity mistake: Before Dr. Marvin removes the helmet from the dead alien, Maj. Huglin is holding his rifle in his right hand. In the next shot he's using his right hand to remove the helmet. Then in the shot after that he's not touching the helmet at all. (00:56:15)
Continuity mistake: When they remove the helmet from the dead alien the front of Dr. Marvin's hair is combed differently than it was earlier in the scene. Carol's hair changes also throughout this scene. (00:56:20)
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: We see the head of the alien up close twice and each time the gravel underneath is raked differently. (00:56:25)
Continuity mistake: We see the alien ship before it destroys the Pacific Paint Company with what looks like a beautiful cloud filled sunset behind it. In the next shot as the building blows up the sky is cloudless. (00:57:30)
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: After listening to the alien translating device from the helmet the general says, "I'll show you how it works" and Maj. Huglin turns to look at Carol twice between shots. (01:00:40)
Continuity mistake: After the general says, "I'll show you how it works" they all turn and follow him. In the next shot they're in an entirely different room. (01:00:55)
Continuity mistake: As Dr. Marvin tries on the alien helmet the microphone on the table that Carol spoke into when they demonstrated the alien translating device is standing straight up. In the next shot it's moved sideways. (01:02:45)
Continuity mistake: As the aliens announce their intentions to the people of earth Dr. Marvin walks up to a radio in the back of the lab and says, "If I'm right they'll sail into Washington in broad daylightÂ…". If you look closely the radio is pointing to a different station that it was when we saw it previously in the scene even though no one has gone near it. (01:04:35)
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: During the final attack the cloud cover is continuously changing. One minute it's clear, than over cast, then wispy cirrus clouds, then puffy cumulous clouds all between shots. (01:13:00)
Continuity mistake: A saucer crashes through the main window of a train station and the clock reads 11:10. Two shots later, we see the clock on the other side of the building, and it reads 10:43. (01:17:40)
Continuity mistake: Carol and Dr. Marvin stand in the front of the Supreme Court Building as the aliens destroy it. As they cut away to the long shots of the front of the building they're not there but then in the close-ups they are. (01:19:05)
Continuity mistake: One of the three trucks used in the movie with the magnetic interference units on them has a distinctive kink in it's dish, and we see this truck destroyed by the aliens. Several shots later when the battle is over this truck is back again. (01:19:05 - 01:20:55)
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.
