Humans fear the unknown, and space is crammed full of it (despite mainly being a vacuum). As such, people are terrified of it in the same way ancient civilizations were scared of an eclipse.
Times have changed, of course, and we know a lot more; we no longer fear the eclipse or other explainable events. However, that doesn't mean all our fears have gone away. People are currently sharing what scares them now about space on an Ask Reddit thread, and it's quite interesting to see what really spooks people at this moment in time.
Let's go through some of the best ones.
Mobile Black Holes
This was the most-upvoted of all the space fears, with user Skyerocket explaining the obvious crux of the issue: "Say one heading straight towards us was discovered... We'd be completely fucked, right? Very little we could do?"
Roving black holes are a thing. We've spotted evidence for one the size of Jupiter casually making its way through the Milky Way. In the unlikely event that one was headed our way – and we spotted it – they are right to say there's little we could do about it, except get eaten. Though there are ways that have been proposed to move our whole Solar System out of the way of a supernova, so let's not lose all hope.
The Kessler Effect
"Here’s one closer to home," Reddit user sosogos joined in. "The Kessler Effect is the theory that a single destructive event in Low earth orbit could create a cascade where satellites break up into tiny fragments taking out other satellites, breaking up into smaller fragments and so on, until the Earth is completely surrounded by a massive cloud of tiny flying death shrapnel, which would make leaving this planet almost impossible. If you look up how much space debris there is already up there and how many satellites currently orbit, plus the continued growth of the commercial space industry... I think about it a lot."
Though this is a genuine problem, the Kessler Effect (or Kessler Syndrome) is more likely to make low-Earth orbit inaccessible, which is obviously a huge problem in itself, given our communication systems rely upon satellites in low-Earth orbit, rather than make leaving the planet impossible.
The Scale of the Universe
A common one (and the one I get the most) is the existential dread you may get thinking about the sheer vastness of space.
"I've seen videos showing the scale of the universe before, but this one really hit home for some reason," user Digibollocks wrote about Dr James O'Donoghue's video below. The speed of light, the fastest speed possible, looks painfully slow when you look at it in the context of even a fraction of our Solar System. We're stuck here, aren't we?
"A few people have said this but just the size of space is creepy to me," one user added. "That far away.... but what almost depresses me more is that unlike in Stargate I will never be able to travel to any of it. Would love to see what's out there."
Most of us will never leave the Earth.
Not all of the suggestions were serious.
"Matter as it is isn’t in its full resting state, and a little surge of energy could shift it enough to completely change chemistry and physics in our universe," one user wrote. "It’s been theorized that there are already these vacuum “bubbles” in space racing out at the speed of light. It’s basically death on god mode."
This one is another that's genuinely a bit terrifying to think about. Check out this video on it if you'd like to experience new levels of dread.
The Great Attractor
This is a lot less sexy than the name implies. There's a gravitational anomaly in intergalactic space, obscured by our own galactic plane, making it difficult for astronomers to observe. Indirect observations suggest a "localized concentration of mass thousands of times more massive than the Milky Way," oh, and it's moving.
Read more about it here (I promise it's more reassuring than you'd expect).
Voyager 1 Will Outlive Planet Earth
This is plausible, and frankly, good luck to it.
Check out the rest of the thread here, and have fun terrifying yourself with things beyond your control.