In October 2014, astronomers got their first glimpse of a monster stalking through our Solar System. The name 2014 UN271, or Comet Bernardinelli-Bernstein to give it its human moniker, probably means nothing to you, but the mega comet barrelling through space is thought to be the largest comet ever discovered passing through our Solar System. And it’s headed right for Earth.
Just kidding. While the 100 to 370 km (62 to 230 miles) diameter comet is an absolute beast, there’s so far no indication that it’s going to come anywhere near us. Space is after all rather big, and despite what humans like to think, we are very small indeed.
But as we scan the skies for space rocks that could potentially end humanity as we know it, another intriguing, and utterly terrifying, possibility arises. Could these rocks in space one day be weaponized by humans?
No doubt some of you watching have just let out a weary sigh – either at the preposterous nature of it all or that we might have yet another potential world-ending event to add to the steadily expanding list to worry about, which includes nuclear weapons, biological or chemical warfare, viruses that ravage the entire world, super volcanoes, mega comets or asteroids hitting earth, the inevitable AI war that is to come, solar flares and of course, the impending doom that is climate change. It’s a cheery time to be alive, isn’t it?
But let’s not get bogged down in the gloom, there’s enough of that around already – says the man presenting a video about weaponizing space rocks that may be able to be used to kill humans.
Anyway, let’s begin with the space rocks themselves. We’ve used this term as an umbrella to include several different types of rocks, but there is sometimes a little confusion surrounding these lumps of alien rock floating through space.
The gargantuan form first spotted back in 2014 is a comet, which is typically formed of ice, dust and rocky material, while asteroids are made up of metals and other ock material. Asteroids are essentially unused leftovers from the creation of the Solar System around 4.6 billion years ago, while comets are generally thought to come from the Oort Cloud, a vast cloud of ice and dust that surrounds our solar system.
And when I say vast, I‘m aware that that word is a vast understatement. While it’s impossible to know for sure how large the Oort Cloud is, estimates place it somewhere between 0.03 to 3.2 light-years across. To give you that in a more human-friendly manner, the Voyager 1 unmanned spacecraft is currently approaching the Oort Cloud and scientists estimate it could take roughly 30,000 years to pass all the way through. If it isn’t smashed to pieces by one of the billion, if not trillions, of objects that compose the cloud.
A meteoroid can originate from either a comet or an asteroid but is usually significantly smaller, anywhere between a grain of sand to a large boulder that you definitely wouldn’t want dropping on your home. If you’ve ever wondered what the difference between a meteoroid and a meteorite is, you’re in luck. Once a meteoroid breaches our atmosphere, it becomes a meteor and if it hits the ground it’s considered a meteorite.
So we’ve established that there are an awful lot of space rocks floating around, but are they dangerous?
To answer that question quickly, and perhaps a little bluntly, let me take you back to the Yucatan Peninsula in modern Mexico around 66 million years ago, when an asteroid between 10 and 15 kilometres (6.2 to 9.3 miles) wide slammed into the earth, ending the 180 million year reign of the dinosaurs. So yes, these space rocks can quite literally end us.
And guess what, this happens relatively frequently. I don’t mean frequently to us humans, but in the grand tale of the earth, it’s a regular occurrence. There are ten recorded impact craters on earth that are less than ten thousand years old, with a diameter of 100 metres (330 ft) or more.
There are more than forty craters around the world created over 10 million years ago which measure at least 20 km (12 mi) in diameter – with 13 of them measuring over 50 km in diameter. Of these, two have been linked with extinction events, the strike in Yucatan I’ve already told you about and the Popigai crater in Siberia which is thought to be linked with the Eocene–Oligocene extinction event which saw large-scale extinction and floral and faunal turnover around 34 million years ago.
Meteors are much more common, with an estimated 500 meteorites making it throughout each year. In 2013, one measuring 20 metres (66 ft) in diameter exploded in an airburst 29.7 km (18.5 mi; 97,000 ft) above the ground over Chelyabinsk Oblast in Russia. The explosion injured close to 1,500 people indirectly, mainly from the shockwaves and falling objects, and over 7,000 buildings were affected as a result. And this was a small-ish space rock.
With such catastrophic results on the table, you might wonder why anybody would even think about trying to weaponize a comet or an asteroid. Well, unless the most despicable super-villain imaginable emerges – think a combination of all of the Bond baddies into one super devil – it’s almost unimaginable that anybody would try to direct a massive space rock into Earth’s path. It would be the grandest, most heinous suicide you could possibly imagine. Unless there was a spacecraft that could take off just in time to escape the inferno – but now I’m getting carried away.
Things become a little – and I do mean a little – more likely when we’re talking about meteoroids or small asteroids. However, again, we’re talking about Bane from Batman levels of organisation and psychopathic tendencies here.
The major problem with something like this is that there aren’t that many floating close to Earth. I know that I’ve just rambled on about how many have hit our planet, but again, we need to think of the big picture. You would probably have to wait around for several hundred years until a suitable asteroid passes by, which I suppose provides a lengthy cooling-off period to consider your murderous tendencies.
But let’s just say that hypothetically there is an asteroid passing close and we wanted to alter its trajectory. In theory, at least, we could launch a spacecraft to travel alongside the asteroid where it would need to remain for several months, maybe even a year, while the spacecraft’s fairly weak gravity could slowly but surely tug on the space rock, pulling it into a different orbit.
This sounds outrageous I know, but there’s even a term for it, the gravity tractor method, which NASA planned on trying just a few years ago. The Asteroid Redirect Mission called for a spacecraft to essentially tow an asteroid and place it into a stable lunar orbit. Of course, there was never any suggestion that the American’s were about to start throwing rocks at Russia or China, but rather the mission was designed so that chunks of rock from the asteroid could be slowly chipped off to be studied. The mission however was cancelled in 2018.
And there was another quite brilliant reason to do this. As I explained earlier in the video, it’s highly likely that at some point in the future a comet or an asteroid will set a course for planet Earth and if there are any homo sapiens still alive at that point, they will need to do something about it. The Gravity tractor method is seen as one of few different methods that humans may have to one day utilize to ward off the apocalypse. We will be coming back to the defence of Earth a little later in the video.
But back to the actual weaponization. The problem around this theory – he says as if there’s only one – is that this method would only really allow us to speed up or slow down an asteroid and wouldn’t be able to alter its trajectory. So if you wanted to manipulate an asteroid to hit a very specific, let’s say Washington D.C or Moscow to go all Cold War, you would need to choose an asteroid that was already passing across that area, which probably adds several hundred more years to the process.
However, when we think about available space rocks that could be used to bombard Earth, we might be looking too far afield. There are also theories that a nation could set up a base on the moon from which large boulders could be launched directly at Earth.
This may sound like we’re nudging into lunacy here but in many ways, this is probably more likely than a nation firing up a spacecraft and redirecting an asteroid to hit the Earth. Once you’d set up a base and organised your mining operations you would then just need to find a way of launching the rocks towards Earth at high velocity.
And remember that gravity is significantly lower on the moon meaning the rocks would weigh much less there than they would on Earth. A ten-tonne rock on Earth would equate to just 1.6 tonnes on the moon, meaning that you could technically pick up something fairly light, hurl it as fast as you can, and when it came down on your specified point on Earth, its weight would be significantly more.
Of course, there are a mind-boggling number of obstacles to this, not least the fact that we haven’t even managed to establish a base on the moon yet. But if you wanted to hurl some space rocks at your enemy back on Earth, the moon might be the best place for it.
While these wild megalomaniac theories to harness space rocks for evil purposes will no doubt appeal to some, the vast majority, I hope, would probably be more interested in how comets or asteroids could be manipulated to save Earth.
As I’ve said twice already but it does pay to repeat, at some point a big boy rock is going to come through and earthlings will have to deal with it or that’ll be the end. Fortunately, we do have several ideas already and still have Bruce Willis lying around as a backup if needed.
And just to go a little sci-fi for the moment, we’ve always assumed that asteroids and comets would come purely by chance, but what if another race started bombarding Earth with regular asteroids? It happened in Paul Verhoeven’s wonderfully rubbish 1997 film Starship Troopers, so you never know. My point is, whether it’s aliens lobbing rocks at us or simply bad luck, we should probably start preparing for these eventualities.
According to NASA, we would need around five years of preparation time to launch a potential asteroid deflection mission, which does sound like a long time, but when you consider that most asteroids are orbiting the sun, we can typically predict their path well in advance.
When we think about destroying a giant rock hurtling towards us, we need to think about either fragmentation or delay. Fragmentation essentially means destroying the object to such an extent that it can no longer harm us, which includes the smaller pieces that can splinter off if not done correctly. Delay just means slowing down or speeding up the object so it and the Earth don’t arrive at the same point in space at the same time.
Earlier I mentioned the gravity tractor method and this is one option that could potentially be used. Their problem here is that you’d have to build a spacecraft of quite sizable proportions then send it out into space where it would rendezvous with the asteroid. This is an option that comes with plenty of complexities but is widely regarded as a realistic option.
From one subtle approach to one that’s entirely less so. Let’s just strap some massive nuclear weapons to a spaceship and blow the bugger apart. Sounds great in theory, but it would be difficult to be sure of complete fragmentation and does leave the possibility of the Earth escaping a massive extinction asteroid, but being pelted with hundreds of thousands of meteorites. Don’t get me wrong, it’s a better option, but still not great. And this wouldn’t necessarily involve crashing the spacecraft onto the surface, but instead detonating the devices at a 20-meter (66 ft) or greater height above the rock.
Alternatively, we can go all Armageddon and use NASA’s Hypervelocity Asteroid Intercept Vehicle, which is still under development, where two crafts would be used, the first to create a crater on the asteroid and the second to dive into it bloated with a massive nuclear bomb that then goes boom. It’s thought that this could be one of the quickest options available to us.
The last that we’ll look at is the idea of kinetic impact which involves a large spacecraft or another near-Earth object, such as another asteroid, smashing into the doomsday rock heading towards Earth. The European Space Agency currently has two separate operations in the pipeline under the Asteroid Impact and Deflection Assessment mission to test just this theory.
The focus of both spacecraft is the small moon of asteroid 65803 Didymos, with the first arriving in 2022 and the second in 2027. These impacts will be small and certainly won’t destroy the asteroid or even affect the orbit too much, but should give those on the ground a much better idea of how this particular concept would play out in a real event.
These aren’t the only theories as there are plenty more, but so far we’re struggling to come to a general consensus on how best to deflect a giant rocking coming towards earth. No doubt this will all come together at the very last minute, which is generally how we do things on this pale blue dot.
A Weapons Free Space
When the Outer Space Treaty was signed in 1967, signatories from around the world pledged to never put nuclear weapons in space and as far as we know everybody’s kept their end of the bargain.
But in recent years there has been some suggestion that we are inching forwards with the militarization of space. Military satellites are now fairly common and several countries have even destroyed their own obsolete or malfunctioning satellites in space.
Then we have to think about what GPS really is. Yes, it can tell you exactly where you are and no doubt is of great help when trying to find something, but let’s not kid ourselves, we don’t need to stretch the imagination to see how this technology could very easily be used against individuals. It’s no great surprise that the European Union, China and Russia all used their own version, instead of the U.S Global Positioning System.
But weaponizing space rocks is probably well out of the realm of possibility for the time being. The simple logistics behind it are staggering and it’s difficult to believe that there wouldn’t be an easier way. However, what is much more likely is that we will develop technology that will allow us to manipulate an asteroid or comet’s path, in fact, it might just be the apocalypse defying plan that saves us all.