Everyone always assumes that the aliens have nothing better to do than invade Earth and serve man, preferably with red wine. (I know that’s what a supposedly smart guy like Stephen Hawking thinks…).
Me? I’m not convinced. I mean, why spend the ginormous amounts of energy and resources that interstellar travel would require to invade an inhabited planet and deal with the irate natives when you can get pretty much everything you need – including water, hydrocarbons and minerals – from an uninhabited planet or Kuiper belt of proto-comets? Simple logistics rules out planetary invasion, in my view. In fact, the aliens would really have only one reason to visit Earth.
That reason would be to talk to us.