What happens is — the moon disappears. Yeah, right in front of everybody’s eyes. One second it is there, shining brightly, inspiring songs containing the words moon, spoon, June, and the next – <poof> gone. Hit by something, maybe some big asteroid, who knows, but the earth folks have taken to calling it The Agent.
It is quickly determined that the explosion, which has shattered Luna into a kabillion pieces of varying sizes, will, in two years, start bombarding the earth with those pieces, and then will begin the period of the Hard Rain, (a rain of rocks) which will demolish all life on earth as it triggers volcano eruptions, earthquakes, and fires completely covering the planet. This will last about 4,000 years, give or take a millenium or two. Well, that sucks.
So the folks get busy creating life boats for space, to be attached to a space station already in orbit. An international lottery is conducted to select passengers to populate the escape vehicles and provide the material to keep the human species viable until such time as the planet can be repopulated.
The first third of the book is about the technology involved in all this, and the politics. The second third is about life in space when earth gets destroyed. Lots more technical stuff, and lots of character-driven action, and lots of action-action. We can think of this section as the Space Opera phase of the book.
The third portion of the book opens on Zero 5000, that is, 5000 years after the moon explosion and the destruction of earth. The survivors, all descendants of the last 8 humans left alive who were all women, have over the millennia raised their numbers to about 3 billion, living on a giant satellite-type ring system in space, and have been terraforming the Earth in order to receive human inhabitants again. OK, not all the descendents are women, they worked out how to get some males, too, eventually.
The book is filled with lots of talk about genetics, parthenogenesis, orbit technology, and all kinds of stuff of which I am only moderately clear about, so I don’t really know how much of it is speculative, real, or just pure nonsense, but all of it was wildly compelling and entertaining, and just all around fun, especially if you like hard science sci fi.
It examines the notion of race, politics based on race, and the idea that character traits can be race embedded. The main characters are writ large, and will serve as the basis for the Next Generation. Two groups, among others, one can only assume, try to create a safe place to ride out the coming apocalypse. One group seals themselves in a deep mine in Alaska, and the other group is on a submarine, and heads for the Marianas trench, hopefully to avoid being boiled like shrimp in a fish stew. Do either of these groups survive? For 5,000 years?
It’s an epic story, improbable and interesting and thought-provoking all at the same time. I loved it.