They just might turn out to be human beings. The Bible does not prohibit the Cosmos being populated by more of us. I think this would be the case even if they don’t look like us. After all, there are many races of us just here on the earth.
I think that would bring up too many logical inconsistencies with what the Bible says.
(1) All humans are sinners (hence all need salvation--including alien humans).
(2) Jesus died once (precludes Jesus incarnating as an alien human on another planet and being sacrificed again)for all (all would include alien humans if they existed).
(3) The Bible states that salvation is though Jesus alone.
(4) God desires all be saved.
Jesus' sacrifice took place on Earth, and the good news of the gospel of salvation is only known on Earth. So any alien humans on another planet would have not access to the gospel and no way to be saved through Christ--which clearly conflicts with point #4 above.
The idea that you could have an entire planet full of humans (or multiple planets for that matter) that had no chance of salvation seems to conflict too much with what the Bible says about salvation to make it a possibility.
How did they get “there”, if you’re using the Bible as your authoritative source?
All humans are descended from Adam, through a bottleneck of Noah, then scattered at Babel, resulting in the races you refer to.
So, how did they get from Adam, or Noah, onto other planets?
The “races” here on earth all descended from one original pair of human beings, Adam and Eve. Battlestara Gallactia aside, there is no record of any other extra-terrestrial race of human beings.
Because of their sin, all creation, the entire cosmos, was subject to futility.
19 For the earnest expectation of the creation eagerly waits for the revealing of the sons of God.Extra-terrestrials is the stuff of science fiction, not true science nor theology.
20 For the creation was subjected to futility, not willingly, but because of Him who subjected it in hope;
21 because the creation itself also will be delivered from the bondage of corruption into the glorious liberty of the children of God.
22 For we know that the whole creation groans and labors with birth pangs together until now. (Roman. 8)