So you think that God would give the creation of the heavens secondary mention, much less importance than the animals on earth and that somehow there could be completely unmentioned life on planets around said stars that are somehow more significant than earth's animals? Can you tell me why God made these intelligent creatures that were not worthy of mention in His Word and placed them around distant stars that we will never visit?
"Not worthy" is an ASSUMPTION.
There is plausibly [even from our finite perspective] . . . plausibly several reasons God chose to mention things as He did.
1. God's priorities for us humans etc. were better served without such a priority given to any off-planet critters.
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2. He didn't mention the civilizations which were clearly or at least evidently flourishing BEFORE the world was "void and without form," either.
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3. It may have mangled the priorities for THOSE critters to have changed the way(s) they were left out of the Scriptural account.
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4. It may have distorted too much God's Good General classified info stuff vis a vis satan and satan's plans with some such critters vis a vis the END TIMES.
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Ummm...As to "why," asking God "why" He does things is a fool's game, as Job learned. Presumably God might make other intelligent beings for the same reason He made us.
With regard to why He didn't tell us about having populated other planets, why should He have told us anything? Was He obligated to? Is it possible that you might stand before God one day and say "God, you made real live Tralfamadorians and you didn't tell us! That's not fair!"
The Lord doesn't owe us insight on this matter. For that matter, He doesn't owe us our next breath. Perhaps he did populate other planets with other beings, just as he populated the earth with us. On the other hand, maybe He didn't. Either way, the prerogative and the power to do so are all His. He is not bound by our extrapolations from Scripture.
The Book is OUR Bible, written for US and OUR salvation.
Why should it extensively discuss things not related to its primary mission?