7 Horrible Ways The Universe Can Destroy Us Without Warning

7 Hypervelocity Stars

What we tend to call shooting stars are really just meteoroids burning in the Earth's atmosphere. But actual shooting stars do exist. Yes, there are very real stars -- as in "great balls of nuclear fire a million miles across" -- with a velocity so great that they can actually escape the gravitational pull of their galaxies and roam free throughout the universe. These freewheeling stars are the Hells Angels of the cosmos: They're big, scary and notoriously difficult to stop, and if they move into your neighborhood, your property values are going straight to hell. Yep, there are sun-size balls of nuclear energy zooming wherever they want at speeds of up to 4,000 kilometers per second, burning everything they come across and fucking up every orbit they pass by. We just thought you should know that, in case you were running low on nebulous dread or something.

How They Will Get Us:

But it's probably OK: We've only found like 16 of these things zipping about. When you take into account the fact that our solar system is but a speck of fecal matter in the giant toilet that is the universe, the chances of one of those ever managing to impact us are roughly the same as the chances of you ever managing to gather up enough courage to talk to that cute girl next door from atop your solid-gold BattleMech.

But the thing with the universe is that it's kind of a largish place. However sophisticated our current equipment may seem, it's still the equivalent of shining a cereal-box flashlight into the ocean to try to spot the bottom. So whenever new technology enters the game, new data enters the equation, and we have to revise our appropriate terror levels for it. For instance, the new Pan-STARRS telescope system has, within the past five months alone, found no less than 19 completely unknown asteroids that pose a potential danger to Earth. And these have been buzzing around a mere 7.5 million kilometers away. Universally speaking, that's not on our doorstep -- that's right in our goddamn living room, ransacking our drinks cabinet and making offhand remarks about our place looking really flammable and how "It would be a shame if anything bad happened to it."

And we're not exaggerating that "hypervelocity" part, either -- an average HV star moves at a staggering 1.6 million kilometers an hour. So while there might not be any hypervelocity stars with trajectories directly threatening Earth that we know of, one could come hauling ass up into our business in a cosmic heartbeat. Plus, the aforementioned 16 are just those that humanity has found and is able to monitor. You know how many are estimated to be bouncing playfully around our galaxy alone? At least a thousand.

There's still precious little chance of hypervelocity stars ever being an immediate threat, though: "Cosmic heartbeat" is still kind of a long-ass time for humanity. If we geared up a new telescope tomorrow only to find one coming in from a previous blind spot as close as, say, one light-year away, we'd still have a few centuries before it would fry us, cause a cataclysmic collision within the solar system, and inflict some pretty intense gravitational disruptions. You're not going to be alive in a few centuries, though; that's the future's problem. And really, fuck those guys. All flying around in their precious jetpacks like they're better than you. They deserve what they get.

6 Rogue Black Holes

It's not just stars that take apocalyptic joyrides randomly throughout the universe. Science has found out that black holes can move about at terrible velocities, too!

Wait, what? Black holes? The great big space-whirlpool crushy things? The ones that you can't escape from, and you can't even see?

Yeppers! Those are the ones. If you thought that black holes were abstractly frightening but that you were safe as long as you didn't go gallivanting about space like some kind of space-asshole, think again. They can -- and do -- move, which of course means they're coming directly for you.

How They Will Get Us:

When it comes to sneaking up on us unnoticed, hypervelocity stars up there have the minor drawback of, well, being giant balls of nuclear fire. They're pretty noticeable. Rogue black holes, however, get a +4 stealth bonus for being notoriously difficult to spot in the vast darkness of space. There could be one coming at us right now -- screaming your name followed immediately by "I COME FOR YOUUUU!" -- and we might never notice it. Well, until it rips the Earth apart, sucks us down and purees us before finally, mercifully adding us to the mass of its singularity. We'd probably notice that part.

And of course there are hundreds of rogue black holes roaming our galaxy alone. We don't know why you even bothered asking.

5 Galactic Cannibalism

Ever put two hamsters in a cage together and then, come next morning, wake up to find only one fat, innocent-looking hamster? This is the same thing. Only the hamsters are galaxies.

No, they're not ... they're not shaped like hamsters. It's an analogy. Jesus.

This phenomenon is called galactic cannibalism, and that's one of those rare scientific names that is as plainly accurate as it is bowel-seizingly terrifying. Basically, smaller galaxies succumb to the gravity of a bigger one and are slowly absorbed into it, thus adding to its mass and making it even larger, so it can eat more galaxies. It's a dog-eat-dog universe out there. Hell, even our own Milky Way is known to indulge in this behavior every once in a while.

How It Will Get Us:

It's not a matter of how; it's a matter of when. See, one of the bigger galaxies that's heavily into eating its kin is Andromeda. You know, our closest neighbor Andromeda -- the "way the hell bigger than our galaxy" Andromeda. See that picture up there? It's not just there to fill space. No, that's a computer simulation of what Andromeda is going to do to us someday. We, as a galaxy, are going to be eaten.

This will cause the two galaxies to slowly compress into a single mess of stars within the next 3 billion years or so, throwing us to the very outskirts of the new Galactic Scramble, or maybe even transforming our very own sun into one of those hypervelocity stars.

And somehow, those are the "nicer" options. Otherwise, our whole solar system could just be devoured by exploding galactic gas or crushed by a colliding Andromedan equivalent.

4 Vacuum Metastability Event

Quantum physics, the study of "dual particle-like and wave-like behavior and interaction of matter and energy," is science-talk for "a bunch of far-out shit, man." The field has sprouted some of the more mind-blowing theories of life, the universe and everything. One of the more disconcerting ones is the suggestion that we (as in "we, everyone and everything in the universe") may exist in a false vacuum state. A lot of abstract terms such as "bubbles" and "vacuum levels" are involved, but in layman's terms, this means the universe was built from dodgy parts and ended up with an energy level too low for more than temporary sustenance. Therefore, at any given moment, it could call it quits and succumb to the pressure, only to be replaced by higher energy levels.

How It Will Get Us:

It's called a vacuum metastability event, which is what happens when the energy levels of our particular universe's vacuum go sour. Should this happen, the ensuing collapse would level Earth with a light-speed blast before any of us even had time to blink. It's probably a good thing that we don't survive long, because after that, things get really bad. All the laws of physics will go psychedelic on your poor, obliterated ass, until they eventually mutate into a completely new, improved set. There will still be a universe, just not the universe. In time, there may even be life -- just not the sort we'd be able to comprehend, even if our brains hadn't been smashed into inverted color parties riding the crest of an infinite mathwave.

In other words, quantum physics is basically telling us that Cthulhu and the Great Old Ones could come knocking at any minute now. That's right: Lovecraft was a scientist all along, just coldly documenting the facts as he saw them.

3 Cosmic Radiation

You know what the universe is? A total dick, that's what.

You know what else it is? A giant microwave oven.

If you tune your TV set between channels, part of the "snow" that you see on the screen is background noise caused by cosmic radiation. You can also hear this phenomenon as a low, humming hiss behind all other noise. It was first found when two lab rats were trying to calibrate a giant hearing horn yet kept getting this strange farty sound no matter how they filtered the results. Of course, that's just the background radiation. There are also plenty of other, more lethal types bombarding us from space at all times.

How It Will Get Us:

While cosmic rays aren't able to deliver microwaves powerful enough to do what an actual microwave oven does (i.e., explode us like hot dogs), other kinds of rays out there are more than capable of harming our machinery and turning us into walking tumor farms. The only thing protecting us is our atmosphere, especially the ozone layer. You know, the ozone layer? That thing we were all going to save back in the 90s and then completely forgot about?

OK! So now there's harmful radiation leaking in every day. And it gets worse the higher up you go in the atmosphere. Do you fly often? Say "hi" to cosmic radiation! Pilot or stewardess? There's an actual measuring system for determining exactly how well-done space wants your ass.

And what about the cosmic microwave background? That stuff just lurking in the snow of our televisions and the background hiss of our audio equipment? Well, it's not going to do much more than loiter, but that doesn't mean it can't still get to us. For instance, if you happen to have a stroke, you'd better hope the paramedics aren't carrying an old-model defibrillator. Because if they are, cosmic microwaves may have already drained the battery, right when you need it most. Maybe that's not the most spectacular way to go out, but it is the most damning and direct evidence that the universe wants you, specifically, as dead as possible, and that it is constantly trying all sorts of things to make that beautiful dream a reality.

2 Gamma Ray Bursts

While cosmic rays can be harmful and even fatal, they're stopped just short of eradicating all life on Earth by our built-in defense system. This shield has given us just enough time, as a species, to develop and understand the concept of smugness, before the universe brings out the big guns.

Enter the gamma ray burst.

The GRB is nothing less than a Death Star-style destruct-o-beam, but on a cosmic scale. It's caused by a particularly massive star collapsing into a black hole, which initiates a supernova explosion, which in turn emits twin energy flares in opposite directions. Each of these flares has energy levels that make even the supernovas that birthed them blush. A typical burst releases as much energy in a few seconds as our sun will in its entire 10 billion-year lifetime.

How They Will Get Us:

If one happens in our galaxy -- basically anywhere in our galaxy -- it could effectively end us by boiling away most of the ozone layer and, following up for a two-hit combo, bombarding the Earth with insane amounts of UV radiation. Luckily, our current measuring equipment says these happen relatively rarely in the universe:

Just once a day.

1 Magnetars

Magnetars are a type of neutron star, and they're what's left when a massive-enough star expends itself in a supernova. They're composed of an ultrathick material called neutronium, a thimbleful of which weighs approximately 100 million tons. Magnetars have powerful magnetic fields that emit huge amounts of high-energy electromagnetic radiation (such as X-rays and gamma rays) as they decay. So basically, a magnetar is an omnidirectional gamma ray burst combined with a cosmic-level EMP.

Come on, universe. At this point, you're just bringing a tank to a knife fight.

How They Will Get Us:

There are no magnetars in our immediate vicinity, but the radiation from even the distant ones could very well damage the Earth. In fact, minor blasts already have: In 1979, a bunch of Soviet spaceships, idling after a satellite drop, were saturated with extreme magnetar radiation. The pulse then went on to screw up three Department of Defense satellites, and we only noticed the damn thing coming when it was already gone. In 2004, another magnetar blast hit. This one was so intense it actually affected our ionosphere. Again, we didn't see it coming until it was too late to do much more than slap at each other in panic. And we certainly didn't expect it to be nearly as powerful as it was. That blast came from 50,000 light-years away; the nearest-radiation emitting magnetar to us is 9,000 light-years away.

What can you say to that, except "shitbricks" or "I've always loved you, Gary"?

Oh, and it should go without saying at this point, but we find more magnetars all the damn time. We guess that's the main thing you should be taking away from this article: There are so very many dramatic ways that vast, incomprehensible galactic phenomena can kill you, that every single day that you go unmurdered by space is a miracle.

Cherish it.

Pauli Poisuo is a freelance writer.

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