Space!

It’s big, and dark, and has more ways to kill you than there are stars in the sky. Or at least, that’s what Science Fiction might have you believe, even if you ignore all the ones caused by aliens.

Now, don’t get me wrong. Space is certainly deadly. And there are some pretty extreme causes of death that would fit right in in some SciFi plot.

They’re just not always the ones you might expect. So let’s look at six ways we’ve seen fake space kill, and then unpack the real ways it might do the deed, instead. [intro jingle] Our first Cause of Death is freezing instantly upon exposure to “outer space”,

by say, taking off your spacesuit helmet to stop another astronaut  from trying to rescue you, or just getting launched out a hole in the side of a spaceship. Do you remember that episode of Magic Schoolbus Where Arnold takes off his helmet And then like, his glasses turn purple and then his face freezes?

And it's like, terrifying? It's this trope. The idea here is that it’s so cold, as soon as a human exposes their fleshy bits to space, they can’t help but turn into a popsicle.

And from a certain point of view, your typical cubic meter of space is cold. The background temperature hovers around -270 degrees Celsius. That’s roughly three degrees above absolute zero!

Meanwhile, dunking your hand in liquid nitrogen… which is 74 degrees warmer than that… is a great way to lose your hand. But while space is cold, it’s also very empty. Not completely empty, technically, but just about.

And that emptiness means that it’s a terrible conduit for heat. There are three ways to transfer heat. There’s convection, where particles take heat with them as they move from hot to cold.

Conduction, where heat transfers through particles in close proximity. And radiation, where particles emit and absorb energy. But there aren’t enough atoms in space to help with the first two, so the only way to transfer  heat in space is radiation.

And with only radiation, if you were jettisoned naked  out a spaceship airlock, you’d basically shed heat like a 50 Watt incandescent lightbulb. At that rate of heat transfer, it would take you more than 10 hours to freeze solid. Unless you were even slightly close to another radiating body  that could keep you warm, like the Sun.

In which case you might never freeze. In some movies and TV, death by outer space is a bit more… explosive. Take the 1980s space western Outland, for example.

I know you’ve all definitely seen that movie. When a valve gets disconnected from a character’s spacesuit, their head puffs up before going pop in a bloody mess on the inside of the visor. Now, while it is true that extremely low pressures can be very dangerous, your head and organs wouldn’t just pop when exposed to the near vacuum of outer space.

The science behind this myth is that a liquid’s boiling point depends on the pressure it’s under. For example, at the top of Mt. Everest, water boils at 68 degrees Celsius instead of 100 because the air pressure is so much lower.

And in the near vacuum of space, water will boil at pretty much any temperature… including body temperature… because there’s no pressure to keep the molecules packed together as a liquid. However, most of the blood  in your circulatory system is well-contained, so it probably wouldn’t boil. Some of the vessels close to the surface might swell or burst, though.

And any water right on the surface like the saliva on your tongue would boil. In fact, this happened to someone during a training exercise in 1966! To prepare for the Apollo  program’s missions to the Moon, NASA built a vacuum chamber to test out their new spacesuits.

But during one of those tests, a malfunction caused the man inside to be exposed to the vacuum. He quickly passed out, and the last thing he remembers is his saliva starting to boil. Luckily, the chamber was quickly re-pressurised, and he lived to tell the tale without any serious injuries.

So in the end, what’s far more likely to kill you upon exposure to the void of space is something far less visually dramatic than freezing or exploding. It’s oxygen deprivation… perhaps exacerbated by some side effects of rapid decompression. And unfortunately, that has  killed three space travelers.

In 1971, a valve in the Soyuz 11 spacecraft accidentally depressurized the cabin while it was still in outer space. The cosmonauts inside were on their way home from the very first space station, and after the craft landed, the recovery team opened the hatch to find them dead in their seats. It’s a unique tragedy in the  history of human spaceflight, because it’s the only time anyone has officially died in space.

So from here on out, any of the ways that space can kill you hasn’t happened to anyone. Thankfully. At least not yet.

Our third way space kills you, as depicted in science fiction, is by having its characters zip through a dreaded asteroid belt. Asteroid belts are often treated as densely packed mazes of space boulders that are nearly impossible to navigate. There’s a certain fictional droid out there that can tell you the odds.

But the truth is the asteroid  belt in our solar system is really sparse. According to one astronomy professor writing for Scientific American, the average separation between large asteroids in the belt is about five million kilometers, which is more than 10 times the distance between the Earth and the Moon. And we have proof that you don’t need to be some ace pilot like Han Solo to fly through the asteroid belt.

Every space mission we’ve sent through it has passed without any major issues. But if you do happen to find yourself flying through space, here are three things you should be afraid of instead of the asteroid belt: First up: a proper set of rings, like the ones around Saturn. When viewed with a telescope from home, Saturn looks like it just has the one ring, but if you look closer, it’s actually a smear of ice and rocks that extends out 282,000  kilometers from the planet.

Depending on where you wanted to fly through, you could be looking at densities of up to 60 kilograms per cubic meter, which…fun fact… is the typical density of insulation you’d use to soundproof a room. With particles ranging in  size from dust-size particles to boulder-sized ones, it’s not as uniform as insulation. Luckily it’s only 10 meters thick on average, so the best strategy is probably just to aim for a gap and pray!

I think that counts as  being difficult to navigate. And back when the Cassini probe was in orbit around Saturn, it dove through an apparently  empty gap in the rings. But the probe still wound  up recording 100,000 hits from dust-sized particles!

Luckily, neither dust nor probe was travelling too fast relative to the other, so those hits were all insignificant “dings”, and Cassini got through the rings unscathed. The second thing I’d be wary of travelling through are the  Van Allen radiation belts. Because of our spinning iron core, the Earth is blessed with a magnetic field that acts as a deflector  shield for energetic particles coming from both the Sun and further afield… Energetic particles that can do things like damage human tissues and shut down spacecraft electronics.

So that protection is good. But the particles don’t just disappear! They get concentrated into two donut-shaped regions roughly 10,000 kilometers and 26,000 kilometers above Earth’s surface.

That’s normally fine, until you want to fly through  them to get to the Moon, or Mars, or somewhere further. If all you’re doing is flying through them, the radiation dose you’d get wouldn’t be anywhere near lethal. But you don’t want to set up camp there.

Meanwhile, Jupiter has its own radiation belts that are much larger and much more powerful. One of its moons, Europa, is smack dab inside one. If you decided to pay the surface a visit, and you didn’t have proper shielding, you’d absorb a fatal dose within a few hours.

And our third and final threat that could kill you as you fly through space is tiny bits of debris. That includes rocky micrometeorites, as well as the stuff we’ve flung up there over the decades. Remember those Cassini dings?

Well, this is kind of the opposite of that. Because of the huge velocities involved in getting stuff  into or beyond Earth orbit, even tiny objects can leave big marks. In low-Earth orbit, where the International Space Station is, objects are travelling just under eight kilometers per second.

Which isn’t automatically terrible. Space debris wouldn’t be an issue if everything were travelling in the exact same direction. But it’s not.

If something is travelling in the opposite direction to the ISS, it would hit our space station effectively traveling around 15 kilometers per second. At those velocities, even something the size of a blueberry would be lethal without shielding. Now before we move on to our next Cause of Death, we need to keep the lights on.

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You can learn more about them, how they got into manufacturing, and exciting manufacturing career pathways you might want to think about by visiting ManufacturingUSA.com/Modern-Makers. Our next Cause of Death is the Sun wiping out civilization… if not life as we know it… with a big, sudden burst of energy. Like a solar flare.

The truth is that our Sun has been super active before, producing both solar flares that spew out light, and coronal mass ejections that spew out matter. But even the worst solar storms only damage electrical equipment. While this could certainly  end your life indirectly, it’s not the end of humanity as we know it.

What really could kill us is a nearby star reaching the end of its life and exploding. Some supernovas are accompanied by a burst of x-ray and gamma radiation that’s so intense, it could kill us even if it has to traverse a thousand light years of space to hit us! . In fact, back in 2005, a few researchers proposed that some kind of gamma ray burst may have triggered a mass extinction roughly 440 million years ago.

Not by directly frying critters, but by destroying Earth’s protective ozone layer, causing an ice age, and  creating a bunch of acid rain! Although luckily for us, when astronomers look for possible supernova threats, they don’t find any candidates that are actually threats to life on Earth. At least for the foreseeable future.

Just like our next subject… In movies and TV, black holes are often depicted like giant cosmic vacuum cleaners, sucking up anything that gets too close. and in the case of Disney’s 1979 movie, The Black Hole, it’s also a portal to Hell! But while nobody has ever visited a black hole, we can immediately debunk  the idea that they “suck.” When you’re far away from a black hole, it acts like any other massive object, and exerts a perfectly normal gravitational pull. If our Sun were replaced by a black hole with the exact same mass, we’d soon be plunged into an eternal night.

But nothing about the Earth’s orbit would change. But it is true that if you could get up close and personal with a black hole, there are some weird… although still non-sucky effects… that would start to happen. One deadly effect is spaghettification, where you get stretched into a long strand of you-getti by the black hole’s gravity.

Because a black hole has so much mass concentrated into such a small space, every centimeter of distance away from it means a big difference in gravitational pull. So if your feet were pointing  toward the black hole, the pull on your feet would be much stronger than the pull on your head. And as you fall closer toward the black hole, the difference eventually gets so great, you get torn into itty bitty pieces in a long, drawn out meat string.

But before that image inspires any nightmares: you’d probably die long before that, from getting smacked by  all the super-heated matter swirling around in the accretion disk surrounding the black hole. If you’re looking for real nightmare fuel, stick around for our final group of space killers. Behold, the “destructo waves  sweeping across all of space, leaving nothing in their wake”.

Definitely a technical term. Technically, these are purely hypothetical, but they do exist outside of Science Fiction. Even books and movies rarely depict them.

That’s because they’re very hard to 1), visualize either on-screen  or in your reader’s head… and 2), write a plot around because your characters cannot see them coming, there’s nothing they can do to stop them, and death will be pretty much instantaneous. The first of these destructo waves is called a PenroseHawking thunderbolt. And it actually starts with a black hole.

See, some astrophysicists hypothesize that if a black hole can spin fast enough, it can exist without an event horizon. That’s the edge that makes a black hole look like a black hole. Gravity is so strong past that point, nothing can travel fast enough to move anywhere but down towards the infinitely dense singularity at the center.

That includes light itself. Hence all the, you know, black. If there were no event horizon, the singularity at the heart of a black hole would be visible.

But our laws of physics wouldn’t be able to predict what would happen, because our equations don’t deal very well with infinite density. So the idea behind a thunderbolt is that if a spinning black hole either formed without or lost its event horizon, physics would literally break. And that breakdown would continue to spread through all of 3-dimensional space at approximately 300,000 kilometers per second.

The fastest thing anything  can travel through space. Including matter. Including light.

Including any signal that a giant wave of broken physics is heading in your direction to obliterate you. But that’s not the only way  space could kill you with an unpredictable, unpreventable death wave. There’s also vacuum decay.

And it’s a bit tricky to explain this one without getting into the weeds, so bear with me. There’s this thing that permeates all of space called the Higgs Field. You can kind of think of it as  an infinitely big piece of fabric that subatomic particles can  roll across and interact with.

Those interactions both give the particles different amounts of mass, and also wrinkle the fabric itself, giving the Higgs field different  values throughout space. So in a vacuum, where there are supposedly  no particles and no mass, the value of the Higgs field is zero, the lowest number it can possibly be. But maybe, that’s not true.

Maybe we just think the Higgs  field is sitting at zero. Maybe it’s really what’s called a local minimum. Like instead of a ball stuck  at the bottom of a hill, it’s sitting in a little divot in the ground a few meters up the side of that hill.

To dislodge the ball, and get it tumbling toward  the real bottom of the hill… or a true vacuum state in the universe… all you need is an extreme enough event to jostle it out of its  seemingly stable position. In the universe, that jostling could come courtesy of, once again, a black hole doing black hole shenanigans. And if the Higgs field suddenly dropped in value somewhere… to a value lower than we thought possible… that patch of space would experience some pretty serious changes in the fundamental laws of nature.

Like the strength of the forces that hold atoms together. A bubble of “true vacuum” would form, and expand in all directions at that exact same 300,000  kilometers per second rate I mentioned before. Eventually, everything in  the universe would decay.

And if that bubble has already formed somewhere? Well, we won’t know until the moment it destroys us. Maybe that’s not the way  you’d prefer space kills you.

But I don’t know, just suddenly ceasing to exist kinda works for me. [ outro ]