With The Hammer of God, Clarke revisits his usual broad interest in the place of humanity in the solar system and the universe with a particular twist, portraying the possible threat of an asteroid colliding with the Earth with such mass and force that a major catastrophe results. The functions of religion and science in human life are variously evident in both the events of the plot and in the "historical background summaries" frequently used to background the plot action of the novel. The summaries and plot action also reflect on humans' capacity to cooperate when faced with common danger, and their tendency to ally with subgroups of a society when they can find support for individual traits, beliefs, or tastes.

Governments in the world of 2110 have been able to gain (or force) consensus on population control and pollution control. Technology has provided computer-controlled housing that...