This is an epic space opera by british SF author Alastair Reynolds, and is the first novel of his that I've finished (I partially read it years ago but stuff happened...and it has to go back to the library before I'd finished)
Anyway the book concerns itself with a crew of comet miners aboard the ship Rockhopper;the economies of the future are fuelled by ice mined from near-Earth comets. Anyway the crew receives a message calling them away from their current assignment. It seems one of the moons of Saturn has moved from its normal orbit, and the crew aboard Rockhopper is diverted to investigate. As they approach the rogue moon, called Janus, it becomes apparent that it is leaving Saturn orbit and is in fact heading towards a distant star...
The book has some cool concepts as you would expect from Reynolds and although it's quite a chunk of a book the action moves at a good pace.
The edition I read had a really cool holographic cover which I only noticed when the flash on my camera phone revealed it.