1 Paris: {checking navigation} Uh oh...
1 Serron: What is it?
2 Paris: The ship is running into a vast cloud of cometary nuclei and rocky fragments surrounding this solar system.
3 Spanners: Yes, they'll be the left over remnants of planetary formation, orbiting at vast distances from the sun.
4 Spanners: Brace yourselves! This is going to Oort!

The Oort cloud is a large cloud of comets and leftover fragments of planetary formation thought to orbit at distances beyond the outer planets. It's named after Dutch astronomer, Jan Oort, who would probably have been teased a lot at school if he'd attended in an English-speaking country.

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2013-09-18 Rerun commentary: In reality the Oort cloud is very sparse. Yes, there are billions, perhaps trillions, of chunks of ice floating around out there, but they're scattered through a space with a volume of roughly 10³⁹ cubic kilometres. Assuming a trillion (10¹²) objects, that gives each object 10²⁷ cubic kilometres of volume to itself on average, making the average separation between objects of the order of 10⁹ (a billion) kilometres - a bit more than the distance from the Sun to Jupiter. That's a lot of space. You're not exactly going to accidentally bump into one.