By Adam Gilmour
Ok, let me start by saying that I’m a big science fiction fan, particularly if it's about space. I like to see what others think of our future, and I find that the freedom of story-telling uncovers so many possibilities.
So allow me to be tongue-in-cheek when I pose this question: Are we ready for an alien attack... and other threats from outer space?
Most science fiction plots involve conflict of one kind or another. Even world-renowned physicist, Stephen Hawking, has warned about the risk of making contact with aliens “vastly more powerful and (that) may not see us as any more valuable than we see bacteria.”
In the sci-fi books I read, our alien visitors would either be highly technologically advanced (able to travel faster than light, manipulate matter at the sub-atomic level, control super AI and virtually unlimited resources); or come from a relatively lower-tech civilisation (that travels under the speed of light, has limited resources and values habitable worlds).
The latter scenario would usually be the one to worry about. Will they bring high-energy weapons like lasers and heavy particle beams, nuclear weapons and antimatter bombs; even (shock, horror) mini black hole generators?
Personally, I think humankind could get to the ‘advanced’ stage ourselves in about 2,000 years, which (in the timeline of our galaxy) narrows down the window of opportunity for our alien antagonists.
Regardless of what we believe, the fact remains that there isn’t a whole lot that we, on planet Earth, could do about most threats from space.
Right now, it takes us years to develop and build anything that could go beyond low earth orbit. We have no real manufacturing capability off Earth; nor have we learnt to extract resources from the moons and planets that surround us.
And no, we don’t yet have the capability to divert - much less destroy - an incoming asteroid. There have been discussions on the different ways to divert asteroids, e.g. by
Painting one side of it (so it would act similar to a solar sail)
Attaching a solar sail to the asteroid (to slowly drag it off course)
Impacting it with a heavy spacecraft (to nudge it off course)
Striking it with a laser beam (to boil off surface water, causing a steam jet to act as thrust); and more!
With these methods, the further away from Earth you start, the better the result. They require quite large masses to be placed a long way from Earth, probably outside the orbit of Mars. And the assets would need to be able to propel themselves with a lot of delta-V, in order to “catch up” with the incoming asteroid.
Perhaps the best answer we have right now could be to use the SpaceX Falcon Heavy rocket to launch a cluster of Dragon capsules, to be used as “asteroid nudgers” or mobile laser carriers, etc. That could be our first baby step towards true planetary protection.
NOT science fiction
On the bright side, all this could be within our reach within the next 100 years if companies like SpaceX and Blue Origin succeed, and if more risks are taken in human spaceflight and exploration. We have a few good ideas ourselves, which we hope to roll out in the next five years.
Given how much money humanity spends on defending us against ourselves, it makes sense to spend a part of that on becoming more active and capable in the space that surrounds us (literally).
Humankind will need to build long-term infrastructure and bases on the moon, asteroids and eventually Mars. We need to be capable of manufacturing big things, generating lots of energy, and making interplanetary travel quick and easy. And we must have learnt to survive (and even thrive) in the hostile environments off-Earth.
(By the way, doing all this using Space 1.0 technologies and methods would likely cost us trillions, versus billions if done with Space 2.0.)
There are of course many other reasons for why humanity should go forth to explore/exploit the worlds and moons around us. But... alien invasions? Killer asteroids?
Some would call these low-probability ‘black swan events’, random and unexpected. (Like that rock from deep space that recently sailed past the Earth.)
Well, we all know what they say about black swans...