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Ganymede Calling
A mysterious signal from Jupiter's moon Ganymede changes everything.
When astronomers detect an artificial transmission repeating every seven days, Earth is forced to confront an impossible question: Are we alone?
Marine biologist Dr. Sophia Sigler joins an international expedition to investigate the source of the signal beneath Ganymede's frozen surface. What begins as a scientific mission quickly becomes a fight for survival when the team uncovers an astonishing secret hidden beneath miles of ice—an advanced underwater civilization that has remained concealed for centuries.
But the discovery is only the beginning.
As ancient mysteries intertwine with cutting-edge science, Sophia and her colleagues learn that humanity's history is far more extraordinary than anyone imagined. Descendants of Earth's lost Roanoke colonists have survived in Ganymede's vast subsurface ocean for more than five hundred years, living alongside an intelligent aquatic species while an even darker threat emerges from the depths of space.
With hostile forces closing in and an alien armada racing toward the Jovian system, humanity must forge an unprecedented alliance to prevent a catastrophe that could enslave not only Earth, but countless worlds beyond.
Grounded in real science and filled with unforgettable discoveries, Ganymede Calling blends first contact, hard science fiction, historical mystery, and high-stakes adventure into an epic tale of exploration, survival, and humanity's place in the universe.
When astronomers detect an artificial transmission repeating every seven days, Earth is forced to confront an impossible question: Are we alone?
Marine biologist Dr. Sophia Sigler joins an international expedition to investigate the source of the signal beneath Ganymede's frozen surface. What begins as a scientific mission quickly becomes a fight for survival when the team uncovers an astonishing secret hidden beneath miles of ice—an advanced underwater civilization that has remained concealed for centuries.
But the discovery is only the beginning.
As ancient mysteries intertwine with cutting-edge science, Sophia and her colleagues learn that humanity's history is far more extraordinary than anyone imagined. Descendants of Earth's lost Roanoke colonists have survived in Ganymede's vast subsurface ocean for more than five hundred years, living alongside an intelligent aquatic species while an even darker threat emerges from the depths of space.
With hostile forces closing in and an alien armada racing toward the Jovian system, humanity must forge an unprecedented alliance to prevent a catastrophe that could enslave not only Earth, but countless worlds beyond.
Grounded in real science and filled with unforgettable discoveries, Ganymede Calling blends first contact, hard science fiction, historical mystery, and high-stakes adventure into an epic tale of exploration, survival, and humanity's place in the universe.
405 pages, Kindle Edition
Published March 28, 2026
About the author
R.J. Millas
6 books1 followerR.J. Millas is a science fiction writer and software engineer with a Master's degree specializing in Electrical and Computer Engineering. He's been an avid science fiction fan as far back as he can remember — enjoying sci-fi books, movies, and tv shows. His hobbies include collecting toy robots, coffee roasting, astronomy, amateur radio, reading, and painting. He has two wonderful sons, Julian and Daniel, and he lives in the sunshine state of Florida with Yvonne, the love of his life, and their dog, Lucy.
His first novel, Brookhaven - The Quorvian Chronicles - Book 1 was published on December 7, 2020.
The second book in the series, The New Renaissance - The Quorvian Chronicles - Book 2 was published on December 9, 2021.
His third book, The Pentarrians - The Quorvian Chronicles - Book 3 was published August 1, 2022.
His latest book, Ganymede Calling (unrealted to his previous trilogy) was published March 28, 2026.
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Displaying 1 - 5 of 5 reviews
October 6, 2026
A good space opera story that blends history and science fiction.
July 7, 2026
Disclosure: I received a free copy of this book.
Ganymede Calling is an incredibly creatively written sci fi novel that I greatly enjoyed reading. Several decades in the future, humans have a space station orbiting Jupiter and a base on Europa looking for life. But when a signal is discovered coming from Ganymede they investigate and find sentient extraterrestrial life – cephalopods in metal exoskeleton suits and humans descended from the lost colony of Roanoke living in a biodome beneath the ice on Ganymede. The Keeuogg, as the friendly cephalopods call themselves, are trying to protect humans from the Hemmokites, others of their race who wish to enslave them. When the brilliant but reckless scientist Sophia goes off in a submarine and is captured by Hemmokites, she finds other captured humans and learns that they are to be sold as slaves to interstellar traders. Fortunately she and the others are rescued thanks to a newly formed telepathic connection, but it looks like Earth will have to go to war.
This book was a real page-turner that I read eagerly. I loved the characters, the thrill of discovery, the budding romance between Sophia and Rob, and the whole concept of the aliens and how they visited Earth centuries ago. I would highly recommend this book to any sci-fi fan.
Ganymede Calling is an incredibly creatively written sci fi novel that I greatly enjoyed reading. Several decades in the future, humans have a space station orbiting Jupiter and a base on Europa looking for life. But when a signal is discovered coming from Ganymede they investigate and find sentient extraterrestrial life – cephalopods in metal exoskeleton suits and humans descended from the lost colony of Roanoke living in a biodome beneath the ice on Ganymede. The Keeuogg, as the friendly cephalopods call themselves, are trying to protect humans from the Hemmokites, others of their race who wish to enslave them. When the brilliant but reckless scientist Sophia goes off in a submarine and is captured by Hemmokites, she finds other captured humans and learns that they are to be sold as slaves to interstellar traders. Fortunately she and the others are rescued thanks to a newly formed telepathic connection, but it looks like Earth will have to go to war.
This book was a real page-turner that I read eagerly. I loved the characters, the thrill of discovery, the budding romance between Sophia and Rob, and the whole concept of the aliens and how they visited Earth centuries ago. I would highly recommend this book to any sci-fi fan.
September 10, 2026
Ganymede Got WILD
A mysterious signal from Ganymede had me curious from the start, especially once Sophia’s determination to investigate kicked into high gear. Girl... your sense of adventure is stressing me OUT! 😂 What begins as a scientific mystery keeps expanding into something much bigger, with strange discoveries, political tension, alien encounters, and plenty of danger along the way. There’s a LOT happening here, and some of the technical explanations became dense enough to slow the pacing for me. Still, the increasing stakes kept me wondering what could possibly happen next. Besties... Ganymede was NOT playing around!
🥀 My ratings and review are my own. 🖤
A mysterious signal from Ganymede had me curious from the start, especially once Sophia’s determination to investigate kicked into high gear. Girl... your sense of adventure is stressing me OUT! 😂 What begins as a scientific mystery keeps expanding into something much bigger, with strange discoveries, political tension, alien encounters, and plenty of danger along the way. There’s a LOT happening here, and some of the technical explanations became dense enough to slow the pacing for me. Still, the increasing stakes kept me wondering what could possibly happen next. Besties... Ganymede was NOT playing around!
🥀 My ratings and review are my own. 🖤
August 1, 2026
Can aliens and humans work together from a common threat?
I liked this exciting adventure and the characters were portrayed exactly in a way you would wish for this book. Mankind has made it to the stars. Jupiter and its moons are being studied from observation posts and all of the sudden, they find life on one and even weirder, they are a combination of alien and human living together harmoniously from Earth's past. they are in danger from slavers looking and finding their location and unfortunately, now Earth is also in danger.
I liked this exciting adventure and the characters were portrayed exactly in a way you would wish for this book. Mankind has made it to the stars. Jupiter and its moons are being studied from observation posts and all of the sudden, they find life on one and even weirder, they are a combination of alien and human living together harmoniously from Earth's past. they are in danger from slavers looking and finding their location and unfortunately, now Earth is also in danger.
April 11, 2026
Outstanding Science Fiction Writing
Ganymede Calling is a very exciting story revolving around Jupiter's moon Ganymede. If you are looking for a story that is believable and backed by good research, this the one. You can relate to the characters and the storyline is fast paced that builds to a crescendo in the end that is amazing!I'm.
Ganymede Calling is a very exciting story revolving around Jupiter's moon Ganymede. If you are looking for a story that is believable and backed by good research, this the one. You can relate to the characters and the storyline is fast paced that builds to a crescendo in the end that is amazing!I'm.
Displaying 1 - 5 of 5 reviews