I really love Neal Stephenson, so it is probably not saying much that I also loved his latest book. However I've spoken with some more objective people about "Seveneves" and they also agree it was excellent.
In the first chapter an unknown "agent" splits the moon into seven large pieces which remain in orbit around the earth and closely clustered together. At first all is well because the relative position and mass is mostly unchanged. But then scientists realize that the fragments will eventually start breaking each other into smaller bits which will rain down on earth and light the sky on fire (estimated to occur about two years after the initial breaking). So humanity scrambles to preserve some small amount of life in a hastily enlarged ISS orbiting earth with the hopes that someone will be able to re-colonize the planet sometime in the distant future when the bombardment has settled down.
There is a lot to love in the book, but something I'd like to call out is how gripping the early chapters were. While reading I found myself occasionally forgetting that the world wasn't actually ending and that the moon was not broken and about to rain hellfire onto the planet. I'd find myself thinking about how I would want to spend my final two years. Super powerful stuff!