reply to post by Akragon
It really depends on how patient any hostile aliens might be.
If, for instance they've traveled in slow ships over tens of thousands of years with their personalities stored in Virtual Reality where they can
print out replacement bodies on arrival, then, they could conceivably set up in the Asteroid Belt and just throw big whopping huge rocks at us until
we're bombarded back into the stone age or even extinct.
They then just continue to wait until all the dust settles, seed the planet with their own fauna and flora, wait some more, and eventually, they've a
new Eden, all human free.
It really depends.
If the Aliens are robots or machine intelligences, then, they might even just ignore us as inconsequential indigenous life, and go about raping the
planet for whatever resources they want swatting us away where we become a nuisance.
If Aliens are more like us than different, they might even use us for food, or pets, or slaves, or lab rats.
There are too many Science Fiction factors to really say.
We could get aliens that recycle us for our brains like that one movie, or something totally different.
The problem with much of Science Fiction is that all the Aliens we seem to encounter (in fiction) use technologies only marginally more advanced than
our own.
These aliens usually still have biological bodies, or personalities stored in a body that can be targeted or fought against, and they use machines.
They're really, in some ways, only us, but different, with more futuristic technologies.
We need break out of that mold and think of things that truly would be alien.
The movie Monsters that depicts a Panspermia seeding event was interesting. There weren't any evil intelligent aliens, but, more like alien animals.
From a practical standpoint, however, if any aliens wanted to wipe the Earth clean of Humans, it'd only take some bit of biological tinkering to
develop a whole zoo of plagues, including alien locusts to drop on the planet and wait for the results.
The other scenario is similar to the Keeanu Reeves The Day The Earth Stood Still where replicating nanomachines simply sweep across the planet like a
sandstorm.
NO.
If there ever were hostile Aliens, we really wouldn't stand a chance, not anything really even all that movie or TV series worthy either. We'd go
out suddenly, or with a whimper, entirely powerless to do anything about anything.