Why Do Aliens Invade Earth?
I can remember vividly my first exposure to Star Wars at eight years old. It wasn’t A New Hope but The Empire Strikes Back on V/H/S, Darth Vader front and center on the sleeve artwork. I wasn’t born until after the original trilogy was released, but at 10 years old I had the fortune to see the Special Editions on the big screen. The year before the UK rating for Independence Day stopped me from going to the theater, so I had to wait until the home video release to see the large scale devastation. Star Wars and Independence Day cemented my lifelong love for science fiction and fascination with space; I would spend hours recreating scenes from my favourite movies with a pencil and paper.
Among my favourite subgenres in science fiction is the alien invasion movie. On screen a cinematic invasion can take on many sizes and forms, through blunt force or a sophisticated infiltration, exploring themes on both the human level and a global scale. When I was younger I didn’t ask so many questions about the invading aliens; they were evil and humanity has to fight them to survive, but as I got older I began to think about the practicalities of those aliens taking over the planet. If an alien species has crossed the interstellar distances of space to overrun Earth they better have a good reason. Now, every time I watch a movie like War of the Worlds I find myself asking…
Why do aliens invade Earth?
I also ask myself how much time and thought screenwriters invest in coming up with a reason. Do they create something novel or instead hand wave the explanation because they can’t come up with something that makes sense? In a dramatic context an extraterrestrial force can unite humanity against a common enemy; in a thematic context an extraterrestrial force can be metaphorical to political, biological and social issues in the real world. For a screenwriter the ‘why’ of the story may not be as important as the allegorical subtext. It can’t be that difficult to come up with a decent, logical motivation for our cinematic invaders.
Breaking down the ‘whys’ into categories can reveal whether an alien invader’s reasons for conquering Earth make any kind of logical sense.
By Design or by Chance
Are the invading aliens an intelligent species flying in spacecraft armed with technologically advanced weaponry? Or is there an invasive lifeform that is simply propagating itself, free of malice or intelligent thought? With the latter the subject of the invasion is more circumstantial rather than deliberate.
By Design: Independence Day (1996), War of the Worlds (1953, 2005), Mars Attacks (1996)
By Chance: The Blob (1958, 1988), Night of the Creeps (1986), Slither (2006)
Earth Centric or Human Centric
Is the invasion built around seizing Earth’s resources with humanity as an inconvenience? Or are humans the single reason for their attempt to take over the world?
Unlike other planets in the rest of the solar system Earth has liquid water, an oxygen rich atmosphere and organic life. Before the Kepler telescope’s discoveries of star systems with potentially habitable exoplanets Earth was thought to be unique and rare, but that idea has subsequently changed. To prospective alien invaders it is questionable what natural resources on Earth would be elusive elsewhere in the universe. What remains unique to Earth is its indigenous life, including humanity.
In many science fiction movies aliens seek to use humans as a slave labour force, as hosts for intelligent parasites, or simply as a food source. The problem with many of these reasons is the rationale and logical conclusions audiences can make about them. For example, why would a technologically advanced interstellar civilization need slave labour when it would be easier to clone a workforce or create robots to serve them?
Earth centric: Oblivion (2013), Battle: Los Angeles (2011), Little Shop of Horrors (1986)
Human centric: Invasion of the Body Snatchers (1956, 1978), The World’s End (2013), V (television miniseries) (1983)
One exception that blurs the line between wanting Earth’s resources or humans is Steven Spielberg’s War of the Worlds. From the visuals throughout the film the audience can infer that the tripedal aliens are terraforming the planet, using humans as the mechanism for the transformation as seen through the red weed.
Alternative Explanations
The reasons for aliens conquering Earth have so far revolved around material gains such as natural resources or exploiting the human population, but an underused aspect for alien invasion stories is an imperial or dogmatic motivation. Making their designs on the planet a mission of conquest or a spiritual crusade would eliminate the practical inconsistencies of why an alien force would choose to invade Earth.
In Tim Burton’s Mars Attacks the reason for the Martians invasion doesn’t appear to be concerned with resources or humanity. Given the comedic methods the Martians use to terrorize Earth their primary motivation seems to be because it would be easy.
Ambiguity
A common device used by screenwriters is to deliberately keep the reason for an alien invasion vague. One justification to not elaborate on the ‘why’ is because the notion of not knowing is itself frightening, similar to the argument in horror movies that what you don’t see on screen will be scarier than what you do see — your imagination fills in the blanks.
A redundant defense that is sometimes claimed by writers is that the ‘why’ is not important to the story, but I disagree. The latter reeks of a writer who cannot find or chooses not to bother with even a semi-plausible explanation. With a movie like M. Night Shyamalan’s Signs the absence of an established or speculative motivation causes the story to collapse under the sheer number of unanswered questions the viewer is left with after the credits roll. This is related to a phenomena called fridge logic; you don’t realize there’s something amiss until the movie is over and you raid the fridge in the middle of the night hours later — there is a moment of clarity where you might verbally cry “wait a minute…”
There have been several on screen incarnations of the Invasion of the Body Snatchers story over the decades, and none of them have provided an answer to the designs of the invading pod people. Humans are replaced with physically exact duplicates with the intention of converting everyone, but what then? Do pod people continue living as everyday humans as if nothing ever happened? Are they the first wave in multi-pronged invasion? Unlike Signs the questions viewers might have about Invasion of the Body Snatchers relate to the internal logic of the story, not the inconsistencies and conveniences of the plot to serve the story.
As much as I would appreciate writers and filmmakers to provide a satisfying explanation for their fictional invasions the truth is that often the ‘why’ is merely the means to an end — it is secondary to action, spectacle and entertainment. Rather than perceiving the motivation of an alien force as a narrative obstacle it should be used to enhance the storytelling, providing a depth to our extraterrestrial nemeses who would otherwise be flat, one dimensional baddies. Or maybe we don’t want to humanize the bad guys because the typical cinematic ending is humanity defeating the aliens and winning the war — making our enemies sympathetic would make any audience celebration or entertainment from their destruction macabre.
In the remote possibility that an alien fleet were to invade the planet I wouldn’t recommend using cinematic presentations as a guide for how to fight back and survive extraterrestrial conquest. In the face of such a scenario we should immediately surrender and hope our overlords treat us kindly, because if we were to stand against a civilization that has the superior intellect and mastered interstellar travel there would be no contest. We would be the ants and they would have the magnifying glass.
Of course, that wouldn’t be entertaining.
Coming soon: Diversity in Life, Representation in Fiction
