Anything not born/created on Earth is an Alien by definition.
Aliens are mentioned plenty of times in the bible.
Abram lived as an alien.
"Genesis 12:10 Now there was a famine in the land. So Abram went down to Egypt
to reside there as an alien, for the famine was severe in the land."
"Genesis 17:8 8 And I will give to you, and to your offspring after you,
the land where you are now an alien, all the land of Canaan, for a perpetual holding; and I will be their God.”
"Genesis 21:34 And Abraham
resided as an alien many days in the land of the Philistines."
Moses admitted he was an alien.
"Exodus 2:22 She bore a son, and he named him Gershom; for he said, “
I have been an alien residing in a foreign land.”
Aliens were even allowed to celebrate passover, provided they fulfilled certain requirements.
"Exodus 12:48
If an alien who resides with you wants to celebrate the passover to the Lord, all his males shall be circumcised; then he may draw near to celebrate it; he shall be regarded as a native of the land. But no uncircumcised person shall eat of it; "
Alien residents had to comply with certain rules - e.g. not working on the sabbath.
Exodus 20:10 But the seventh day is a sabbath to the Lord your God; you shall not do any work—you, your son or your daughter, your male or female slave, your livestock, or
the alien resident in your towns.