It’s the most basic terror that science fiction can provide – not only are there aliens out there, but they want what’s ours and will stop at nothing to get it. Alien Invasion stories are a staple of the genre, but they’re often undermined by the failure of the writers to do some basic preparation before they begin – such as understanding the laws of physics. Or biology. Or economics. Or common sense…

So I’m going to go over a few of the major problems and suggest solutions writers could use...