Well how else can you explain it?
3 seconds sound clip from the X Minus 1 - Mars is Heaven by Ray Bradbury classic radio dramaseries.
You can hear this line at 00:11:45 in the radio play.
Quote context
[...]
- This looks like the town I was born in.
- Well, it, it looks like my hometown too.
- I thought of something, sir! It's the only solution.
- Maybe we're not the first ship to reach Mars from earth.
- Don't be ridiculous, Lustig.
- Well how else can you explain it?
- No, there's got to be some logical reason.
- I think perhaps you might find out, Captain. A light just went on in the house.
- Kingston, cover that door with the machine gun.
[...]