Happens every 18, 20 years, they say.
4 seconds sound clip from the The War of the Worlds (1953) movie soundboard.
You can hear this line at 00:15:11 in the DVD version of the movie.
Quote context
[...]
- Who?
- Where do you think they come from?
- I read someplace Mars is near the Earth right now.
- Happens every 18, 20 years, they say.
- Maybe these are not men. Not like us.
- Everything human doesn't have to look like you and me.
- If it's men from Mars, we ought to let them know we're friendly.
[...]