I find references, unmistakable proofs, of the existence of other inhabited planets throughout the OT and the Kabbalah.
Mars, of course, formerly was a delightful inhabited planet: we are even told that "What Earth now is, Mars once was; what Mars now is, Earth will some day be." In the NT, Peter says the Earth will be burned up and left without inhabitants.
Sumerian myth even explains the present global warming, if any. Perhaps. It says that when Olam [Nibiru] starts to get closer again on its long circuit of the nearby universe, the Earth starts to warm up as if to welcome it.
"Cursed be Meroz, and cursed be its inhabitants," says the OT. In the Talmud, a rabbi and his disciples meet an ET one day, and ask of him in Hebrew, what planet he comes from. He apparently knows Hebrew well and tells them. "Oh, really! exclaims the rabbi, I had no idea that planet had inhabitants! ...and they go on and have quite a friendly chat.
Enoch, after leaving Earth, is said to have visited a number of different inhabited planets, and the characteristics of some of these races are described. On one, he is said to be able to see seven moons in the sky at once.
In the book of Job, the leading representatives of all the inhabited worlds come together before God in a regularly scheduled meeting, and Satan attends as the god of THIS world.
Very recently, I heard Billy Graham say again that Satan IS the god of this world.