In his acknowledgments, Clarke notes that the theme of an asteroid striking earth has been used in Shiva Descending by Gregory Benford and William Rotsler (1980) and Lucifer's Hammer by Larry Niven and Jerry Pournelle (1980). The first novel he knew by title; the second he had read.

A short story, "The Hammer of Thor," by Charles Willard Diffin in Astounding Stories (August 1932) also influenced his thought. Place names for Mars he has taken from the NASA "Atlas of Mars" (1979). The title The Hammer of God Clarke took from a G. K. Chesterton Father Brown murder mystery.