It is estimated that the ELE (Extinction Level Event) asteroid that killed off the dinosaurs, known as the Chicxulub impactor was about 10 to 15 kilometers in diameter. That's about the size of a small city. A very SMALL city. Like the smallest city in Rhode Island small.
When we think of how such a relatively small thing such as that can cause such a huge impact, in every sense of the word, on our world, it can be disconcerting to think of random, floating objects out in space. Things that aren't held securely by strong gravitational forces, keeping them in orbits of other, larger floating things in space. Like our Sun holds all of its planets in place, orbiting safely without crashing into each other. No one likes to think that we could be taken out by some random thing not following the Space Traffic Laws, dictating who has the right of way when coming to an established orbital path.
But now, scientists have found a rogue planet out there, untethered to a solar system. It's out there, going rogue, doing as it pleases with no one or no thing keeping it in place. And this ain't your old dinosaur sized rocks either.
It. Is. HUGE.
It is estimated to be 12 times the size of Jupiter!
However, this "rogue planet" is still quite a ways from Earth, estimated to be about 20 light years away. Even more encouraging, those who would know best, those scientists who discovered it in the first place, don't seem to be too concerned about a mash up with Earth. Not anytime soon, anyway.
Still... it's a little bit chilling thinking that it's out there. Cool, yes. But chilling.