Columbia Pictures

“Surf's up dude! Ah, no. It's an alien invasion"Columbia Pictures

Late on Feb. 24, 1942, reports of flares and blinking lights in the skies over southern California caused a succession of nervous alerts. Only three months earlier, the U.S. had entered the Second World War after the shocking attack on Pearl Harbor by Japan, so it is understandable that the West Coast was on the look-out for enemy aircraft.

By the early hours of the following morning, on Feb 25, military radar detected an unidentified flying object 120 miles offshore approaching the coastline. This was followed by reports of a squadron of aircraft over LA and a balloon-borne flare over Santa Monica. A barrage of gunfire from anti-aircraft artillery was ordered, causing the skies to erupt “like a volcano," according to eyewitness reports.

This may sound like the storyline from a work of fiction, but “The Battle of Los Angeles" definitely happened in the early morning of Feb. 25 and will forever fuel UFO conspiracy theories.

Indeed, this event inspired the most recent alien invasion movie, “Battle: Los Angeles," where an aggressive alien race attacks Earth.

The storyline focuses on present-day LA, and rather than the 1942 false alarm being caused by jittery war nerves, the anti-aircraft guns were actually shooting at an extraterrestrial “scout" spacecraft spying on southern California nearly 70 years before the aliens landed.

Movies featuring angry aliens are always fun (unless you had to sit through Spielberg's “War of the Worlds," that is), but ignoring our obvious uneasiness with the phantom alien menace that might lurk in our galaxy, there is one question that keeps popping up in my mind: Why would extraterrestrials attack us?

Resources? A Strong Dislike for Humans?

You could counter that question with: Why wouldn't they attack us? but either way, the answer is as speculative as the search for extraterrestrial life itself. There's no precedent for life beyond Earth, we only have Earth Brand™ Life to work with. And no, I don't believe for a second that they have visited Earth already.

So, looking back at our own history, the root causes of most conflicts are resources and ideology. If one country has a resource another nation wants, they might take it, with force. If one nation has a different ideology to another, they might attack that perceived threat.

This is a massive oversimplification of warfare history, but it is a fact that our planet possesses massive resources; would a resource-hungry, sufficiently advanced alien civilization want to take our resources for themselves? Would they take it with force?

Having said that, aliens might just turn up, unannounced, wanting to exterminate us for no reason (as most alien attack movies would have us believe). It might not be about resources, perhaps they just want to be the only intelligent life form in this region of the galaxy? Perhaps killing things is their ideology.

But now I'm speculating about the beliefs and motivation of an alien race, which is well beyond the scope of even my imagination.

Why Assume They're Friendly?

Last year, world-renowned physicist Stephen Hawking caused a storm when discussing the possibility of alien invasions in his Discovery Channel documentary “Into the Universe." For some reason, the international press went nuts when they found out that Hawking believes our encounter would be less like “ET: The Extraterrestrial" and more like “Independence Day."

Hawking's argument was that perhaps mankind should stay quiet and refrain from trying to send signals into outer space. After all, we have no clue about the nature of these hypothetical aliens, why assume they're friendly? In principal, I agreed with Hawking's concern, but not trying to communicate with other beings in our galaxy could resign us to a dull and ultimately self-destructive future.

(There's also the point that perhaps any aliens in our backyard should be worried about us. We have an awful track record of living in harmony with the other species' on our own planet. Remember “District 9″'s “Prawns," poor guys.)

Hawking's main concern was that a fleet of alien spacecraft could turn up wanting to strip mine the Earth for its bountiful resources. Any life would be just brushed off, like ants off an apple.

“Nope, they don't look friendly to me either" Columbia Pictures

Grim Living

In a recent article by Ken Croswell for National Geographic, my blog “Life is Grim on the Galactic Rim" was quoted when discussing the likelihood of life in the outermost reaches of our galaxy. The upshot is that studies show the galactic rim as being a very bad place for planets, and therefore life, to form.

One study, by Chikako Yasui of the National Astronomical Observatory of Japan, showed that young stars in our galaxy's outermost reaches lacked protoplanetary dust disks due to their low metal content (i.e. any element heavier than helium). This means that the young stars are anemic and planet formation is rare.

If any planets did form, it seems logical to assume they would have a very limited supply of the materials required to support a growing, advanced civilization.

This study serves as a reminder that other star systems are not like ours; depending on where you are in the galaxy, there's a variation in the supply of resources. If a space-faring alien civilization came from one of these “less fortunate" systems — or they've simply exhausted their supply of once-bountiful resources — that would be a potent motivator to explore other star systems, claim resources and expand their civilization.

How long could it be until one of those hungry alien races come knocking on our door? Would they send out a diplomatic attaché to negotiate for the resources under our feet? Or would they dispense with the pleasantries and nuke the natives without a second thought?

“Aliens? Where? LA normally looks like this" Columbia Pictures

I'd argue that if it's just about resources, an alien race probably wouldn't bother pillaging Earth. As we know by now, the galaxy is teeming in worlds to exploit, and many in our cosmic neighborhood will contain similar materials to Earth. There are far easier pickings out there rather than landing on a planet filled with a civilization that takes great pride in building big weapons that could hinder attempts at mining the planet.

So, what is the motivation behind the invading hoards of gun-toting extraterrestrials in “Battle: Los Angeles"?

They want us dead. Our aliveness offends them.

Either that, or it's their idea of a vacation, Malibu is lovely this time of year.