This novel, with a new introduction by Robert Silverberg, tells of the end of the world in the 25th-century, when a comet threatens to collide with the earth. T... » 

This novel, with a new introduction by Robert Silverberg, tells of the end of the world in the 25th-century, when a comet threatens to collide with the earth. The consequences of this event are far-reaching, and set in motion many changes that will profoundly affect the planet far into the future. «