Quora answer: Are angels and aliens the same thing?
Quran sorts some of this out at least for Muslims.
Quran identifies three intelligent creatures: Men, Angels, and Jinn.
Jinn and Men are duals of each other but have freewill, Angels do not have freewill.
The reason that Angels do not have free will is that if they did then the revelation could be corrupted.
Jinn are invisible made of Fire and Air and Men are visible made of Earth and Water.
But there is this very interesting story that two angels came to the people in Mesopotamia and taught them magic but at the same time warned them about how dangerous it was. So this is the one example of a negative revelation via angels from God which to my mind is a very interesting idea.
Aliens on the other hand, are in fact projections of us. Sometimes they are made to look like we expect Jinn to look like. A lot of time what we are talking about when we talk about Aliens are Jinn. Jinn are in fact the Greek gods, they are Fairies. They are ubiquitous in anthropological records of different cultures. They are our duals and because of that they are not truly other.
Aliens are truly other and so that strangeness and opacity can only come from out of ourselves.
If actual aliens showed up, we would not comprehend them be cause they would not relate to any of our projections of the Other either.
There is a great book that captures the shock on the faces of tribes peoples when they first saw White men who were explorers called FIrst Contact. That shock was profound. The were looking at other human beings but they saw them as their dead ancestors coming back from the grave. They saw them as their dead sons, or dead husbands, or dead uncles raised from the dead. Seeing the white invaders as walking death (considering what they had done to other invaded cultures) might not have been too far from the truth. But be that as it may, the point is that what is most shocking is ourselves.