"Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space."
That quote is how Douglas Adams opens his classic work "The Hitchhiker's Guide to the Galaxy," and despite its humorous take, it's actually true. There really is no way to visualize just how huge the universe is - even our own solar system is too big to imagine.
That's why even through there are millions of objects flying around in our corner of the solar neighborhood, it's very rare for them to run into each other. And that's a good thing for us Earthlings.
Now I'm sure you've seen the disaster movies where asteroids hit the Earth, and - for once - Hollywood isn't exaggerating what would happen.
It's also why there's such a fuss when something even comes close to Earth, like the asteroid 2014 RC.