First published in English in 1931, this novel for young adults is an accurate mirror of many of the space travel concepts that have been discussed by pre-war European experts. The author’s imaginative theories about the history of the Earth—many of which presage those of Velikovksy and von Daniken—are explored, and the original illustrations are included as well as an afterword about the author and his sources.

Otto Willi Gail was one of the most popular science fiction authors in Germany during the early 20th century. He wrote several novels as well as books on physics, engineering, and space travel. Ron Miller is the former art director for the National Air and Space Museum's Albert Einstein Planetarium. He is the author of Bradamant, The Dream Machines, Palaces and Prisons, Silk and Steel, Velda, and the Worlds Beyond series and the coauthor of Cycles of Fire and The Grand Tour. His work has been featured in Air and Space, National Geographic, Newsweek, Scientific American, Sky and Telescope, and Smithsonian. He lives in South Boston, Virginia.

Robert Godwin is the space curator at the Canadian Air and Space Museum and an advocate of the Space Frontier Foundation. He is the author of Apollo 11, The Illustrated Collector’s Guide to Led Zeppelin, and The Lunar Exploration Scrapbook. He lives in Burlington, Ontario.