I'm reading Niven's 'Lucifer's Hammer.' I just realised, about halfway through the book, that I'd read this a looooong time ago. Years and years ago. What a great read. Very realistic.
Yeah. Thought I'd add, for those who aren't familiar with this book, it's about a comet strike on Earth. Actually, multiple comet strikes....ouch! I won't ruin any of it for you, but if you like these kinds of sci-fi disaster type stories, this is a real good one. Lots of interesting characters to lead you around the event and well paced, complex and well researched to boot. I got this one on the advice of some fellow forum members and they were right on with it.