Seveneves by Neal Stephenson

It's a routine extended space flight.  The astronauts on the space station are ready for an extended work assignment of a year or more.  But when an event causes the moon to explode, everything known becomes unknown.  Astronomers quickly realise that the debris from the moon explosion will inevitably cause the destruction of the Earth's atmosphere and thus the destruction of all life on Earth.

The expected time frame is two years and the best and brightest minds try to come up with a plan for the human race to continue.  Obviously, the best hope is space and soon every spaceship available is put into service taking up supplies, scientific knowledge and those lucky few deemed important to the human race's continued existence.  The inevitable happens and all those on Earth's surface are soon gone.  There are several thousand inhabitants in space, surely enough to continue.  However, the human characteristics of power attainment and subterfuge create a situation in which after several years, only a handful of humans survive.

Five thousand years later, those humans have survived and thrived with a sophisticated technological society and several billion inhabitants in space.  Plans are moving ahead to solve the problems of the Earth after the land destruction and new plants and animals are stocked there once the atmosphere is stable.  This is to support the eventual return of humans to Earth.  But as the plans progress, it becomes clear that there are surprises in store on Earth and that the story has other chapters yet to be written.

Neal Stephenson writes novels which explore large ideas and Seveneves is no different.  The reader is forced to consider what would be essential in a worldwide disaster and what characteristics would allow the human race to survive.  The ability to cooperate in order to survive and even thrive is explored as is the need for flexibility to handle whatever situations may evolve.  This book is recommended for readers of science fiction and those interested in survival thinking.