Why might Aliens invade Earth?
I’ve seen some discussion about this recently. Trouble is we can only speculate on what an Alien civilization’s motives might be, since we’ve never actually encountered any. We can speculate based on how our own history has been, or might have been. Human wars are mostly over resources, territory, or religion (and just occasionally because someone’s girlfriend ran off with someone else).
It seems unlikey that an advanced race capable of interstellar travel would invade Earth for its resources as there’s plenty just floating around out there free for the taking.
It could be that Earth’s environment is appealing to them. All they have to do is remove the humans – the rest of the planet’s life forms really don’t care much who thinks they’re in charge.
The most likely reason would seem to be religious or idealogical, but again we can only speculate on what forms those might take. It’s tempting to think that scientific and technological progress should go hand in hand with social and moral progress, but I don’t know if that’s always the case. It could be they advanced to a point but then somehow a militant sect of their society seized power and began converting the rest to their cause. Again, we can only speculate.
Lastly of course we may inadvertantly insult them somehow. Or there’s a plan to beam the internet into space, so maybe they just got sick of our spam and being made to watch how we mate.
Also don’t panic – I’m not proposing that it’s actually likely at all. I don’t believe that it is since a civilisatian advanced enough to get here could easily satisfy it’s own needs without relying on conquest. It’s really just a sci-fi scenario.
Might as well look at some fictional alien invasions and the reasons behind them.
War of the Worlds – The original portrayed an interplanetary rather than interstellar war. The Martians own planet was dying so they decided to just hop over to the next one rather than work on technology to fix their own world. Intelligent life of Mars was thought a real possibility at the end of the nineteenth century, but so far we’ve found no evidence of bear sized squidy-creatures riding giant tripods on Mars today.
Dalek Invasion of Earth – The Daleks invade Earth to… turn it into a giant spaceship? Even though they already have spaceships with which they were able to invade? It’s kind of dumb.
Independence Day – Aliens invade Earth to strip it of it’s resources. But it seems an awful lot of trouble to go to when there lots of resources floating in space they could just take without any resistance.
Signs – Aliens who can be killed by water decide to invade a planet whose surface is mostly water in order to… help Mel Gibson get his faith back, I guess? It’s kind of dumb.
V – Um, they want to eat us, I guess. Because they can build huge spaceships but somehow never figured out farming or how to grow synthetic meat. Also they steal our water even though it’s, again, a relatively common substance in the universe.
Battlefield Earth – I had no idea what the hell was going on in this movie.