UFO's and aliens from other planets are an example of religion and science combined into a modern hybrid. These visitors from another planet, have never been proven to exist, yet there is a faith in science logic that infers these should exist. This takes faith since it lacks direct proof. These aliens are often projected as being higher than human, like superhuman gods. Some people have even claimed to have had contact with these aliens; burning bush to get instruction. These prophets are misunderstood.
I believe that thousands of years of religious behavior, beginning at the formation of civilization, has become engrained in human behavior genetics. Based on natural selection, anyone who was part of their local religion would have selective advantage over the disbeliever. They would less likely to be killed by the majority. There was a concentration of genes, over thousands of years, with religious behavior disposition.
Just because atheism wants it to go away, it is not easy to change long term genes in a short period time. The bottom line is it is easier to take a person out of religion, than religion out of the person. The UFO and aliens mythology is projected from within, when people try to become atheists on the surface, but have religious behavior genes. Because of the religion connection, it will parallel the schema of mythology, but make use of modern science to give it an acceptable flavor. They can't believe in God since atheism says, no, but they can believe in aliens since science says yes.