Yes they are real because different people have reporting seeing aliens and also seeing ufos. Some people even report alien abductions even though people dont belive them. And its basically impossible for earth to have the only signs of life on it. Other planets probably have some signs of life on them but they just havent been discovered yet. And these other living organisms from another planet would be known as aliens. As most people say seeing is believing thats why most people believe that aliens exist because they have seen aliens before. Or maybe they have seen ufos. They galaxy is too big for us too be alone.