The Hamner-Brown comet, separately but concurrently discovered by a pair of very excited amateur astronomers, was still a very, very long way from the earth in a typical high eccentricity orbit having barely begun its descent toward the sun. As the world's telescopes are trained on the incoming comet and its orbit is calculated to higher and higher degrees of accuracy, the possibility of an impact with the earth escalates to an uncomfortably high probability. The minute changes in mass and momentum, outgassing and the resulting small changes in the comet's orbit caused by the sun's radiation make it impossible, even up to the moment of actual impact, to accurately predict whether the comet would graze the earth's atmosphere, pass it by entirely or devastate earth with a direct impact.
Panic begins to tighten its grip on the world as a zealous fundamentalist preacher whips the US into a religious frenzy suggesting that the comet is a punishment from God visited upon a wicked humanity. Hoarding begins and roads clog as the population begins a mass exodus from coastal cities in anticipation of the possible tsunami that would result if the comet landed in the ocean. Even a joint Apollo-Soyuz mission sent into space to study the comet, now dubbed "The Hammer" by popular media, is unable to confirm or refute its potential collision with earth.
The final result is perhaps the worst of all possible outcomes. The Hammer does fall, having broken up into several smaller comets that land around the world with devastating results, striking parts of Europe, Africa, the Gulf of Mexico, and both the Pacific and Atlantic. Volcanoes and earthquakes are endemic around the entire Pacific basin as fault lines shift in California and everywhere else along the fabled Ring of Fire. Tsunamis ravage every conceivable inch of exposed ocean coastline and upstream for miles along major rivers such as the Mississippi. Weeks of non-stop rain liberally loaded with salt from the ocean impact drowns a devastated world for weeks after the initial impact and flooding destroys practically every dam and levee, leaving a search for food a top survival priority. Civilization simply falls apart as people are forced to defend themselves and whatever they were able to salvage from one another. "Lucifer's Hammer" is Larry Niven and Jerry Pournelle's graphic but frighteningly realistic vision of humanity's descent into anarchy and chaos and its struggle to re-establish a semblance of normality after an apocalyptic event devastates the world with inconceivable damage and death but does not actually push humanity over the brink of extinction - hoarding; heroism; brutality; the potential change in attitudes towards sex, sexuality, racism, marriage, religion and love; the evolution (or devolution) of government from democracy into potential more effective alternatives under the circumstances; the re-establishment of innovation and technological expertise; the potentially changing roles of women in a more basic almost feudally structured society; and, of course much more.
Most readers would class "Lucifer's Hammer" as science fiction. However, I believe it is fundamentally an exciting thriller and a very impressive extended essay on the psychology and anthropology of humanity's behaviour in the face of global tragedy. The science of the comet, its formation in the distant Oort cloud, its orbit, its structure, its evolution as it accelerates towards the sun and the aftermath as the remnants race away from earth back into deep space, is touched upon but only in a cursory fashion. Sci-fi fans will probably think the book relatively weak in this area and would have hoped for much more depth in the science. Thriller fans, on the other hand, will see "Lucifer's Hammer" as an exciting post-apocalyptic novel that just begs to be turned into a movie with an enormous budget for special effects.
From my perspective as a long-time fan of classic sci-fi, "Lucifer's Hammer" gets only three stars. Others, less concerned about the science will doubtless rate it higher. I recommend that you read it and judge for yourself. You'll enjoy the book no matter which genre your tastes favour.
Stephen King's 'The Stand' was virus, Robert R. McCammon's 'Swan Song' was nuclear, Thomas Disch's 'The Genocides' was alien plant growth, Walter J. Williams 'The Rift' was earthquake; and 'Lucifer's Hammer' is annihilation by comet. Each of these books are 'must have's' for fans of Apocalypse Fiction. The major protagonist is Tim Hamner, a rich-boy with nothing to do but indulge his fascination with the stars. Hamner, along with a young boy named Gavin Brown from Iowa, discover … more
Product Description The gigantic comet had slammed into Earth, forging earthquakes a thousand times too powerful to measure on the Richter scale, tidal waves thousands of feet high. Cities were turned into oceans; oceans turned into steam. It was the beginning of a new Ice Age and the end of civilization. But for the terrified men and women chance had saved, it was also the dawn of a new struggle for survival--a struggle more dangerous and challenging than any they had ever known.... "Massively entertaining." CLEVELAND PLAIN-DEALER