So ABC has greenlit a series that will reboot the old "V" mini- and TV series, where alien lizards wearing human masks come to Earth to steal our water and take our women and eat our rodents and even eat us.
I actually was fond of the miniseries when it came out, silly as it was. The Nazi allegory was done pretty well. It was subtle at first, then built up until it was obvious (right down to the Hitler youth wearing brown shirts and the Nazi-esque flags). I gagged when an alien bred with a human woman -- I had to explain to a friend who saw no problem with that that she was unlikely to give birth were she to go at it with a Gila monster -- but other than that it was fun.
Still, the science of the show... why come all the way here to get our water? There are giant comets in the outer solar system that are dozens of kilometers across that could last a species centuries! Not only are they easier to get at than coming all the way down our gravity well to the Earth's surface, but they're already in a convenient solid form, ready to pack and go.
And eating us is silly-- our proteins would likely poison them. And why pick Sirius as their home star? Given that it has a white dwarf companion, that means that it was once in a system with a red giant star, which would make any planets orbiting Sirius a rough place to evolve.
So, just in case the producers, Scott Peters and Jason Hall do an ego-search using Google and find this blog entry: you need a science advisor. One who loves science fiction, and knows the science of aliens and planetary invasion (I even wrote a whole chapter about it in my latest book). Let me help you. I'll even eat a guinea pig if it helps.