Stephenson’s main characters for this first section include Dubois “Doob” Harris, a black astrophysicist and media personality who bears no small resemblance to Neil deGrasse Tyson. “Seveneves” is about the sort of people who, when the moon blows up, have to figure out what to do about it. The usual fictional apocalypse these days is viewed from the perspective of Joe or Jane Average, some poor slob who barely understands what’s going on and who just wants to get back to his or her family. Yet this is a matter-of-fact bravado, with all the hysteria scrubbed out of it. “Seveneves” begins with panache: “The moon blew up without warning and for no apparent reason,” goes its first sentence. They’re all that’s left of the human race will they be able to keep it going? Is it even worth the try? In the book’s pivotal scene, eight women sit around a battered conference table in a former space station fastened to a clump of rock hurtling through space. Its first part recounts the desperate attempt to save humankind from an unimaginable catastrophe and the second is a knowing interrogation of just how difficult it is to leave our species’ past behind.

Neal Stephenson’s sweeping new science-fiction novel, “Seveneves,” is a post-post-apocalyptic yarn.

Or does it? Humanity could really make something of itself, these stories suggest, if only we could first clear all these people out of the way. Every post-apocalyptic tale is a utopian dream in disguise, which makes our current cultural obsession with the theme - from TV series like “The Walking Dead” to literary fiction like “Station Eleven” - a little less mystifying.

The seveneves