The universe hates you. Let's get that out of the way right now. The universe loathes your guts and is infuriated by the way you dress, and the stupid way you talk sends it into a murderous rage. It's just one bad morning and an empty coffee canister away from driving to your house and shanking you in the neck. With a supernova. It may happen tomorrow, or it may take billions of years. The universe is patient. It can wait. But rest assured: Some day, when you least expect it, it will reap a terrible vengeance from you. And it will go a little something like this:
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.
The stars want you dead. Just FYI.
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.
If you ever meet a woman who's impressed with your bat'leth skills, it's probably time to start worrying.
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."
"How about Earth? They're loaded. Send over a couple of asteroids to rough up the joint."
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.
The whole universe is basically a grab bag filled with medical waste.
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.