And for some time our astronomers have been noticing an unusual amount of atomic activity on the moon.

5 seconds sound clip from the Radar Men from the Moon - Moon Rocket (S1E1) movie soundboard.

You can hear this line at 00:03:33.635 in the Blu-ray version of the movie.

Quote context

[...]

- Not bombs. No planes have been observed, and the explosions aren't severe enough.

- No, from what I've learned of the nature of the blast, they see more like an atomic ray of some kind. Of course that's just a guess.

- It's the same guess that we've made because it's the only possible answer.

- But no one has ever been able to make an atomic ray machine.

- You mean no one on earth ever has.

- Say, this rocket we're building we'll be able to fly to the moon, maybe someone up there's built one that could get down here.

- We believe that possible.

- And for some time our astronomers have been noticing an unusual amount of atomic activity on the moon.

- Atomic activity on the moon.

- Atomic blasts on the Earth.

- The two known facts fit together.

- Yes, it adds up.

- So that's why you want us to fly to the moon.

- Yes.

[...]