Big Books of 2026

Join the Goodreads Author Program

Are you William K. Hartmann, author of the books below?
A Traveler's Guide to Mars by William K. Hartmann Mars Underground by William K. Hartmann Searching for Golden Empires by William K. Hartmann Cities of Gold by William K. Hartmann The History of Earth by William K. Hartmann Moons and Planets by William K. Hartmann Cycles of Fire by William K. Hartmann In the Stream of Stars by William K. Hartmann Origin of the Moon by William K. Hartmann The Cosmic Voyage by William K. Hartmann


To join the author program as William K. Hartmann, you will first need to sign in to Goodreads. Then navigate back to this page to apply.


About the Author Program
Authors on Goodreads
Author Guidelines
Author Program How-To
Author & Advertisers Blog
Ask the Author: Featured Authors
About Goodreads