The Angry Red Planet (1959)
"Men of Earth, we of the planet Mars give you this warning. Listen carefully and remember. We have known your planet Earth since the first creature crawled out of the primeval slime of your seas to become man. For millennia, we have followed your progress, for centuries, we have watched you, listened to your radio signals and learned your speech and your culture. And now, you have invaded our home. Technological adults, but spiritual and emotional infants. We kept you here deciding your fate. Had the lower forms of life of our planet destroyed you, we would not have interfered. But you survived. Your civilization has not progressed beyond destruction, war and violence against yourselves and others. Do as you will to your own and to your planet, but remember this warning - Do Not Return To Mars. You will be permitted to leave for this sole purpose - Carry The Warning To Earth. Do Not Come Here. We can and will destroy you, all life on your planet, if you do not heed us. You have seen us, been permitted to glimpse our world. Go now. Warn mankind not to return unbidden."