Planets on the Move: SF Stories Featuring World-Ships

Recently, we discussed science fiction stories about naturally occurring rogue worlds; there is, of course, another sort of wandering planet. That would be the deliberately-impelled variety, featured in stories in which ambitious travellers take an entire world along with them. This approach has many obvious advantages, not the least of which is that it greatly simplifies pre-flight packing. This spectacular notion has appealed to SF writers for nearly a hundred years; perhaps the first instance is to be found in Edmund Hamilton’s 1934 “Thundering Worlds,” in which every planet in the system is propelled across the interstellar gulf to escape a dying Sun. (As usual, if you know of an earlier publication, let us all know in the comments.)

Here are some further examples of the wandering world in print and/or film.


In Fritz Leiber’s The Wanderer (1964), the eponymous world-ship is a habitat as large and massive as the Earth, equipped with a faster-than-light drive whose appetite for fuel is as great as the ship itself . Unfortunately for humanity, the vessel is filled with trillions of beings (the ship uses not just its surface area, but its volume as living space) and those beings are self-centered enough to rip Earth’s Moon apart for fuel without worrying about what this catastrophe might do to the primitives of Earth. Cue a disaster spectacular filled with megadeaths and very sexy catgirls, neither of which was enough to prevent The Wanderer from being perhaps the second-worst novel ever to win a Hugo (IMHO, and in the opinion of many others; we can discuss in the comments).

I mention the novel largely in the hopes that someone will be inspired to revisit the plot. Even if their version isn’t all that good, odds are that it will at least be an improvement on the original.


Jerome Branch Corbell, protagonist of Larry Niven’s 1976 fix-up A World Out of Time, fled across gulfs of space and time at near light speeds in the hope that, by the time he returned to the Solar System, the authoritarian state of 2190 that resurrected him in a stranger’s body would have withered away. By the time he returns, three million years have passed. That is not long enough to explain the great changes in the Solar System. Not only has the Sun become a red giant billions of years ahead of schedule, the Earth now orbits a weirdly hot Jupiter. Someone has altered the Sun and someone—not necessarily the same person—has moved the planet; how and why account for large parts of the plot (though the overriding theme seems to be disco-era male anxieties about the War Between the Sexes).


Crawford Kilian’s 1989 standalone novel Gryphon depicts an Earth transformed, not necessarily for the better, by first contact. None of the advanced civilizations with which humanity is now in contact have constructed ships able to traverse and survive the vast gulfs of space that separate inhabited star systems. But these civilizations can communicate. Mere communication has upended life on Earth.

Worse is coming. One alien race is so fanatically devoted to spreading their faith that they have set their planet in motion. They don’t have a ship; they have a planet. They plan to convert the universe. Earth’s Solar System gains a new planet, and Earth must deal with some unpleasant neighbours.


The origins of the world-ships in Kameron Hurley’s 2017 The Stars Are Legion are unknown. What is clear is that the fleet of worlds is ancient and that the worlds are reaching the limits of their service lifetime. As world-ships fail, surviving craft fall on each other for necessary resources.

Zan wakes with no memory of her past, only assurances that she is in some mysterious way key to accessing the resources of the world-ship Mokshi for the people of Katazyrna. Perhaps she will save the Katazyrna. Perhaps she will be its doom.


Frant Gwo’s 2019 spectacular SF film The Wandering Earth (Chinese: 流浪地球, Pinyin: Liúlàng Dìqiú) is based on Liu Cixin’s 2000 novella of the same name. Faced with the Sun’s impending transformation into a red giant , the united Earth has strapped rockets onto our planet and launched itself on a thousand-year-plus journey, in a bid to save at least a remnant of humanity. A generation after setting out, the planet is approaching Jupiter for a necessary gravity assist. But as Jupiter grows ever larger in Earth’s sky, “gravitational spikes”  knock out the vast Earth Engines propelling the planet. If the engines cannot be restarted, the billions who died in the name of the migration project will have sacrificed their lives in vain.


A curiosity noted while researching this essay: I can see no reason why this genre would be a male domain. Yet, save for the Hurley, all the examples I found were written by men. This must be due to some research failure on my part. Enjoy pointing out in comments all the books by women I should have mentioned.

In the words of Wikipedia editor TexasAndroid, prolific book reviewer and perennial Darwin Award nominee James Davis Nicoll is of “questionable notability.” His work has appeared in Publishers Weekly and Romantic Times as well as on his own websites, James Nicoll Reviews and Young People Read Old SFF (where he is assisted by editor Karen Lofstrom and web person Adrienne L. Travis). He is currently a finalist for the 2020 Best Fan Writer Hugo Award and is surprisingly flammable.



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