Check out myths, legends and biblical history. Beings flying to the clouds.....yeah, right.
See thats the problem with this debate. If you take the strict biblical side of it as written there are many questions.....but if you take the scientific side of it and carry the science as far as it will take you including the cutting edge of quantum mechanics and such you end up with mostly the same questions.
The very basic watered down version of the Many worlds Interpretation of quantum mechanics is that any and all possible outcomes of every decision and event in history actually happened and that the result of those happenings fractured off into parallel universes. Possibly up to an infinite amount.
I look at it this way, if you take the strict biblical version you must follow where it takes you, and conversly if you accept the strict scientific version you must follow where it takes you. So from a strictly scientific viewpoint the mathematics of it clearly leads you to conclude that we are not alone in this galaxy much less in this universe. And given the age that science says the earth and the galaxy is vs the meager few seconds that humans have inhabited the earth in galactic time, science concludes that it is entirely possible that we are the late comers to the whole show and that intelligent life in some points of the galaxy and universe have several million years head start on us.
So if you are of the scientific side of the argument, yeah beings flying into clouds is one possibility.
Where we have the problem scientifically speaking is that our little undeveloped brains have trouble processing such ideas We simply are not developed enough to handle what our telescopes and math is showing us. If you believe what the hubble telescope is showing us is true and that the milkyway galaxy is only one of hundreds of thousands of galaxies, if even just one planet per galaxy mirrors ours, that is hundreds of thousands of other intelligent civilizations out there.
In this debate which ever side you take you cannot just stop at what you are comfortable with, you must follow your chosen faith or science to its conclusion. Otherwise your argument has as little merit as your opponents does on the other side.