Seveneves

The Moon breaks apart for no known reason. Within two years its fragments will fall on Earth in a hard rain that scorches the surface and leaves it uninhabitable for thousands of years.

Governments pool their resources to send as many people as possible into orbit. They go to the International Space Station and to a swarm of habitats called the Cloud Ark. The first two parts follow roboticists, astronomers, geneticists and politicians who must keep a fragile community alive while Earth burns below.

Supplies run short, factions form, and the survivors face hard choices about who lives and how humanity will be rebuilt. The tone is that of a disaster story told through problem solving, with the detail of orbital mechanics, robotics and genetics worked through on the page.

Part three leaps forward by five millennia. Survivors' descendants now live in a complex society in orbit, split into separate peoples, and an expedition heads down to an Earth that has been transformed.

At about 860 pages in hardcover, the book suits readers of hard science fiction who like to see how each solution works. It won the 2016 Prometheus Award for Best Novel and was a Hugo Award finalist.