The authors, both professional astronomers, propose two theories: (1) that the number of “short-period” comets impacting Earth from about 1000 to 5000 BCE was much higher than today, and (2) that worldwide mythology of gods and “cosmic serpents” originating in that era was actually describing specific comets.
In the first half of the book, the authors explain the current understanding of cosmology as it applies to Galaxies, comets, and asteroids, and propose their modifications. Reading about how astronomers' develop their theories is very interesting, but also challenging for a non-scientist to follow.

In the second half, the authors review mythology and Biblical stories, and suggest how the large number of Earth-impacting comets might have terrorized people throughout the world and motivated much of the mythology. Then when the number of comets diminished, the source of the mythology was gradually forgotten, although the myths remained. The ideas really does seem plausible, but hard for a non-expert to assess how likely it is. The authors deserve credit for being very well informed non-experts.

This book was published back in 1982, so it would be nice to know whether any part of the book has been accepted or rejected in the last 33 years. On the internet, I was only able to find four book reviews written immediately after publication:
(1) Journal of the British Astronomical Association, reviewed by Howard Miles, 1982.
(2) The Observatory, by Mark E. Bailey, June 1983.
(3) Irish Astronomical Journal, by P. A. Wayman, January 1983.
(4) Journal of Historical Archaeoastronomy, by John B. Carlson, 1986.
The first three provide good, technically knowledgeable (with respect to cosmology), summaries of the book. The reviewers are generally open minded towards the theories, while refraining from fully endorsing them. The fourth is quite critical of the book and overly sarcastic. Yet, these sentences by Dr. Carlson stand out: ”As an astronomer who has done primary research on active galactic nuclei and the consequences for galactic structure, I expect that their theory for spiral arm formation will eventually be shown to be incorrect. The ideas about cold cometary planetesimals in the spiral are is quite intriguing.” If one theory cannot yet be shown as incorrect, and some other ideas are intriguing, then I think the book has some scientific merit, regardless of any future scientific discoveries that “eventually” show the theories to be wrong. This is just how the scientific method works.

There is obviously some similarity between the ideas of this book, and the ideas of Velikovsky ( Worlds in Collision, Ages in Chaos). The authors devote a few pages discussing the similarities and differences. Although they believe Velikovsky's physics to be incorrect, and say so rather bluntly, they at least give him fair hearing. This is in contrast to many other scientists who vilified Velikovsky in a most unscientific manner.

This book is well written, and worth reading, if the subjects interest you. ( )