Bath Digital Festival saw us delve into all aspects of our three main themes: Sport, Cities, and Space. But few sessions at this year’s festival had such a compelling, if terrifying title, as “Threats from Space a.k.a. ‘Ah, we’re all going to die!’”
We were guided through this alarming and fascinating topic by the thoroughly engaging Nick Howes, former Deputy Director of the Kielder Observatory, in a talk that cast light into those dark regions of space where existential threats to humanity lie, and how technology can be our saviour in our battle against them, those “Threats from Space.”
What scares us about space?
There’s a lot out there that should:
Black holes? Yes, definitely scary and absolutely not something you want to go near. The nearest one is a mere 1,500 light years away. A notable contender, but not the scariest thing out there.
Supernovae? Some stars of a certain size see the huge battle of forces within them result in a collapse, going (in what feels like an understatement) “bang.” Fortunately, not many near us are due to do so. There is one, Betelgeuse, found in the constellation Orion that is expected to explode, but that could still be another 100,000 years. When it does, it will be brighter in the sky than the moon.
Not them, then.
How about gamma-ray bursts? These can be seen billions of miles away when a neutron star collapses. When it happens more energy is released in about eight seconds than in the nine billion years of our sun’s life.
Definitely scary, but not near enough to worry us.
What about the most popular threat shown in books and films for generations – aliens? Well, there have been recent discoveries, such as a meteorite in Antarctica that seemed to contain a small worm, tinier than anything on this planet. It could be a geological structure, but it could also mean we’ve discovered aliens. Across the universe, there are places with the potential for water and life, and when you consider the number of galaxies (two trillion), the number of stars within each galaxy (100 billion), and the average number of planets per star (1.6), you end up with such ridiculously large numbers that habitable planets seem highly probable.
But despite the math being on their side, aliens are not our biggest threat.
The biggest threat to human life is comets.
What is a comet?
Comets are like cats—they’ve got tails and are completely unpredictable
But in slightly more scientific terms, they are formed of ice and dust. They can have tails 200 million kilometres long, despite being made up of only a few swimming pools’ worth of material. They’re tricky to spot due to their poor reflectivity and only show up when they light up.
If you spot one, you get to name it—but don’t be the one to name the one that’s going to hit us, or everyone will hate you.
What makes them even trickier is that ongoing mass and structure changes, caused by their icy composition thawing and freezing, mean bits fall off, and their trajectory changes. But despite their wandering paths and unreflective nature, we actually see them a lot, as they’re everywhere.
You should start getting scared now.
So, where do these scary things come from?
First up, there are Long Period Comets. These call the Oort Cloud, on the edge of our solar system, home. There, you’ll find a shell of about 800 billion to 1 trillion comets that bump into each other, sending some toward the strongest gravitational pull around – the sun. They can take millions of years to drift towards it, picking up speed all the while. Around the orbit of Jupiter, the energy from the sun is enough to make them light up, and the gases and dust start coming off.
Before that, they have just 25% of the brightness of coal – see “tricky to spot” again.
Oh, and when they get to Earth’s orbital area, they’re moving at up to 200,000 mph.
So that’s one kind of scary comet.
As we move into our solar system between Neptune and Pluto, you’ll find the Kuiper belt, home to 800 million comets. A step closer brings us toward the asteroid belt between Mars and Jupiter, which has millions of asteroids, some practically the size of Wales. If something from there makes its way towards Earth, we have around six months before it hits us.
But the threats aren’t done yet, as orbiting even closer to home is all the space debris we’ve created: old satellites the size of school buses, gloves, and flecks of paint traveling at 8 km/s – certainly enough to kill you if you were out for a relaxing spacewalk. Also for an extra scary kick , when these deorbiting bodies collide with the atmosphere, they create pollutants. In fact, 10% of the sulphuric acid in the stratosphere is caused by satellites.
What happens if they hit?
We’ve got some examples to draw on:
The Barringer crater in Arizona was formed by a meteor about 50 meters wide. It punched a crater 1 mile wide and 560 feet deep in about 1.3 seconds. Anything within about 600 miles would have been killed.
In 1908, the Tunguska event flattened more than 200 square miles of trees in Siberia, thanks to a meteor.
More recently, in Russia, in Chelyabinsk, a meteor 17 meters wide was completely missed as it entered the atmosphere because everyone was focused on a different asteroid the size of a battleship. It created an airburst with the power of the Hiroshima bomb in the upper atmosphere.
But this was relatively small—the meteor that wiped out the dinosaurs was 10 kilometres across. So we really don’t want to see one of that size.
What can we do?
There’s been a lot of doom and gloom, but this article promised solutions and how technology can be used to prevent us from going the way of the T-Rex and friends.
There have been more than a few solutions offered to fend off the annihilation of our species. Gravity tractors to drag the comet away, but they’d need about ten years to get out there, and considering how fast these comets are moving, it’s a bit of a non-starter.
Some have suggested paintballing the asteroid to change its orbit by brightening its surface. This would require about 20 years to be effective, so again, a non-starter.
What about the classic “Nukes in Space”? Well, the longest-range missiles can only get about a third of the way to the moon, and we need to be hitting things around Mars’ orbit. NASA’s DART mission did change the orbit of a tiny asteroid, but unfortunately, we didn’t know until some time later. When it may or may not be too late.
Other ideas include space lasers, harpoons, and nets, none of which surprisingly hold much hope – especially as lasers shot in space can end up anywhere, given the nature of lasers.
The only solution is a fleet of starships in space ready to deploy when required, and the only country, company, or person with the means to do so is Elon Musk, whose focus in space is elsewhere.
For better or for worse, Elon Musk dominates the space economy, which isn’t great, because for planetary defence, we need large space agencies—not the private ventures or misadventures of Elon Musk. Detecting and stopping asteroids should be a big priority for us. The moon is thought to have been a long-suffering bodyguard of Earth when it comes to asteroids – some of the craters caused by them there are the size of France…
Some say asteroids are nature’s way of asking how the space program is going.
Based on this, we may be found wanting.
Added to which the clock seems to be ticking as we can detect and date mass extinction events thanks to coral reefs, and they tell us we’re overdue.
Conclusion
Space wants to kill us – this is now abundantly clear. But the solutions to prevent this are available; in fact, the technology is either extant or currently in development. To deliver it, we need to see a unified effort from national space agencies with a focus on preserving the Earth. It can be done, but don’t expect a Bruce Willis-style rescue à la Armageddon—rated the least scientifically accurate film ever, with over 817 technical mistakes. Instead, picture the even more bombastic sight of a fleet of starships descending upon asteroids before they get anywhere near us—which would still look pretty cool when accompanied by Aerosmith.
Nick Howes was formerly Deputy Director of Kielder Observatory and has over 20 years of experience working at the cutting edge of Research and Development as a synthesizer engineer. His roles have included Sci-Comms for the European Space Agency, Communications and Online Development for the SKA Telescope, and Pro-Am Programme Manager for the Faulkes Telescopes, helping to discover scores of new asteroids. He has given talks all over the world, working with Apollo astronauts, flight controllers, as well as project scientists on a huge range of projects.
Nick is a Fellow of the Royal Astronomical Society and currently works as a test engineer in Space R&D for BMT Defence and Security, the architectural team behind the QEC Aircraft Carrier, with offices worldwide.
