A Deepness in the Sky is a science fiction novel by American writer Vernor Vinge. Published in 1999, the novel is a loose prequel (set twenty thousand years earlier) to his earlier novel A Fire Upon the Deep (1992). The title is coined by one of the story's main characters in a debate, in a reference to the hibernating habits of his species and to the vastness of space.
Background
The plot begins with the discovery of an intelligent alien species on a planet orbiting an anomalous star, dubbed OnOff because for 215 of every 250 years it is dormant, releasing almost no detectable energy. During this period, the planet freezes and its fauna go into hibernation. The planet's inhabitants, called "Spiders" by the humans for their resemblance to arachnids, have reached a stage of technological development very similar to that of Earth's humans in the early 20th century, although humans believe that they may once have been capable of space travel. If this is true, then whoever can establish ties with the aliens first could reap unimaginable rewards; humans have made contact with only one other intelligent (but non-technological...