Why cometh the alien invasion?

I have been catching up on the alien invasion show Falling Skies and it got me thinking about why aliens would choose to attack and invade Earth. You just have to ask why aliens would cross the void between stars to invade a small world like ours. I know this has been hashed over before but if you’re visiting here I figure you might be interested in my thoughts.

Now, right off the bat I want to dismiss the whole idea that they are here for our resources. There is so much raw material floating around that it would be crazy to go deep into a gravity well to get some liquid water or stacks of gold. Even something like oil has to be easier to make than steal from a bunch of cloth wearing monkeys.

So, why would they come? To answer that we need to think about what is unique about our little blue green marble. My short list boils down to: habitat, culture, biology and technology. To varying degrees all of these have the potential to draw in hostile aliens.

Habitat seems an unlikely reason, but certainly possible. For aliens to come here for a new home you have to assume that there aren’t many other options. Maybe there aren’t many Earth like planets close enough for them to use. That is possible, especially if their technology for extended spaceflight is limited. Given the number of planets we are finding with our limited observations, I don’t expect there to be a small number of Earth like planets. However they may be mostly inhabited, which would also limit choices to those easily conquerable. Whether Earth falls into that category is very debatable. If other civilizations followed our development curve there have to be easier targets.

Technology is an odd one of course, but there is every possibility that we have or soon will develop some kind of technology that would be of interest in aliens. I don’t consider it to be highly likely, but it is possible that we could develop something that could interest aliens or scare them enough to wipe us out before we pose a larger threat.

Biology is actually an interesting one to me. Even though there might be some similarities between alien life, there is almost certainly a lot of significant variation. It is not hard to consider that aliens could come here to harvest the Earth in much the same way we do. It is even conceivable that they would find us hairless monkeys to be useful as a conscriptable labor force. I would hope they would use robots for that, but it is a risk nonetheless.

To me the most uniquely valuable thing on Earth is our culture. Any resource argument can be fended off by the notion that it is easier to get the same resources without invading a planet. Cultural artifacts are a different class however. There is only one Mona Lisa or Empire state building. In terms of unique treasure it is our culture that is the biggest prize. Of course that very fact makes it hard for aliens who want our culture to invade. It would be too easy to damage and our creation of new work would be greatly reduced if they launched a genocidal invasion.

Of course culture can cut both ways. While our cultural artifacts might draw in the aliens, their culture might call for our extermination. We have plenty of xenophobic cultures on Earth that would happily wipe out different groups of ‘outsiders’, there is no reason that an alien race might not set out to cleanse the galaxy of other life, intelligent or otherwise. In some ways this is the largest threat given that most other scenarios seem unlikely at best.

In the end I don’t consider an alien invasion to be a large threat, even if I enjoy reading, watching and writing about them. If aliens bother to come all the way here, we are pretty cheap to buy off. It is far easier to subvert them to conquer as modern history demonstrates time and again. Unless they want to rid the galaxy of our quantum entanglement bombs or they really dislike smelly hairless primates, we probably shouldn’t worry too much.

Of course this is just me rambling. I would love to hear your opinions.