It marks an encounter with a part of you that you find strange or incomprehensible. It may feel hostile or contrary to you. First, you need to figure out what it is, and also, why you reject it. Perhaps, you have been behaving in an unusual way lately. It is a mistake not to accept this fact. What at first seems terrifying, over the time can become a great help for success. In addition, the alien can be yourself. The cause may be a recent event, such as a new job. Getting used to a new environment often makes us feel like real Martians. Many people believe that aliens are another product of modernity, so there are no traditional interpretations of this dream.