What unique fear do martians or other aliens represent as opposed to zombies vampires and types of monsters

Martians or Aliens, oppose to Zombies and other monsters, cause a unique fear because of the fact that outer space scares us. I mean, why shouldn't it? Space is a cold desolate place bigger than we could possibly imagine, whereas the earth, where we live, is mostly explored. That's not even including all the rumors about Alien cover-ups by the government.

closer examination, however, finds the mcdonald's kind of job highly uneducational in several ways. far from providing opportunities for entrepreneurship (the lemonade stand) or self- discipline, self-supervision, and self-scheduling (the paper route), most teen jobs these days are highly structured — what social scientists call “highly routinized.”  

true, you still have to have the gumption to get yourself over to the hamburger stand, but once you don the prescribed uniform, your task is spelled out in minute detail.  

no : /