In Dark Eden, I imagined how life might exist on a sunless planet

Eden, the planet in Chris Beckett’s Dark Eden, drifts outside the Milky WayMcCarthy's PhotoWorks/Shutterstock I came up with the idea of the planet Eden in 1992 for a short story called The Circle of Stones. At that time, I had no idea that there really were such things as planets without suns, but it seemed likely to me. It also seemed possible to me that life might arise on such a planet, since, even here on Earth, whole ecologies thrive without sunlight around thermal vents in the deep ocean. Life on Earth may have even have begun in such places. Quite often, if something seems likely, it does indeed happen. (In another book, I predicted that a US president would one day seek to take over Greenland and Canada.) Having written that story, I learned that free-floating planets did indeed exist. Being dark, they’re hard to spot, but a number have been detected using gravitational lensing. And I gather it’s not particularly controversial to think that some of them might support life (though not quite in the form that I chose to imagine it – but I’ll come to that). When creating a world for a story, I don’t usually seek to make the whole thing scientifically accurate, but I try to make it hang together in a way that feels coherent. I didn’t build Eden by doing a lot of research, but I did put a lot of thought into how it might all work. This wasn’t so I could put it all in the book – no one in Eden knows this stuff and the story is told entirely by its characters! – but so that I had something to guide my imagination and make my invented world feel coherent. Advertisement if( window?.adverts?.addToArray ) { window.adverts.addToArray( { "pos": "mid-article-slot" } ); } Free newsletter Sign up to Book Club Sign up to newsletter My idea was that Eden had once been covered in ice, but its hot core meant there was liquid water below the ice in which life could come into existence. One particular kind of life form appeared, somewhat resembling tree roots, that was able to obtain additional energy by pushing deep down into hot rocks, pumping its sap through them to heat it, and then pumping it back up again, like a geothermal power station. One of the ways these organisms used this heat was to push upwards into the planet’s shell of ice, melting parts of it, feeding on the nutrients it contained, and creating more living space – and they carried on doing so until much of the surface of Eden was ice-free, and had an atmosphere that would turn out to be breathable by humans. Millions of years later, this thawed-out surface, now populated by a multitude of different life forms, became the stage on which my drama could unfold: first that early story, then another story and then the novel Dark Eden and its two sequels. In Dark Eden, a tiny community of humans, descended from stranded visitors from Earth, eke out a living using tools made of stone and wood, and try to make sense of their life as exiles from a sunlit world that lives on in folk memory, but which they can only very shakily imagine. (In the biblical story of Eden, humans are exiled from Eden – my Eden is the place of exile.) Their stories tell them that Earth people could fly through the air, that there was a thing there called leckytrickity, that Earth animals had eyes that you could look into and see their minds looking back out at you, not like the flat, blank eyes of Eden creatures. Read more Our writers pick their favourite science fiction books of all time On the surface of Eden, those root-like life forms put up structures that Eden’s humans call “trees”. A whole ecosystem has evolved around them, including “starflowers” that parasitise their roots. (These, as it happens, turn out to be a rich source of Vitamin D. Phew! What a stroke of luck!) And there are many animals – or quote-unquote “animals”, strictly speaking, since they’re not related to the animal kingdom of Earth. There’s no sunlight in Eden (and therefore no alternation of day and night) but, like organisms that live in the ocean depths of Earth, Eden’s life has developed bioluminescence. The “trees” have luminous “lanternflowers”; the starflowers glitter. Imagine a leafless forest on a moonless night, lit by thousands of Chinese lanterns. Then add in twinkling fairy lights at ground level. With your eyes half-closed, the forests of Eden would look something like that. Just as life on Earth depends on plants that turn sunlight into chemical energy, so the life of Eden depends on geothermal trees. They bring heat to the surface to power their metabolisms, they keep the air warm and, if you live on Eden, the steady “Hmmmph hmmmph hmmmph” of their constant pumping is the background of your waking and sleeping life, merging in the distance to a steady hum. All the trees are hot, and some of them are so hot that you’d burn yourself if you touched their trunks. If you cut down a tree, you have to watch out for the spurt of scalding liquid that bursts out. When I read stories set on alien planets, I’m sometimes disappointed in the “animals” (I’ll drop the inverted commas now). Writers often seem to dream up a motley collection of bizarre creatures without much regard for how they might actually survive or how they are related to one another. I tried to design my animals on evolutionary principles, giving thought to how they were adapted to their environment, the role they played in the ecosystem and how they might plausibly have evolved. Animals on Earth fall into a large but finite number of basic body plans. For example, monkeys, cows, crocodiles and seagulls all have four limbs and, though some descendants of quadrupeds have lost their limbs (snakes, whales), there are no examples of quadrupeds developing extra ones. In the same way, large animals on Eden all have a six-limbed body plan. There are other animals that don’t conform to this, just as there are arthropods, et cetera on Earth, but the large animals are all based on this six-limbed pattern. The 12 best science fiction books of 2025 From drowned worlds to virtual utopias via deep space, wild ideas abound in Emily H. Wilson’s picks for her favourite sci-fi reads of the year I’ve already mentioned how different Eden eyes are from the eyes of terrestrial animals. They have evolved alongside the evolution of bioluminescence, rather in the way that colourful flowers and nectar-eating insects have evolved alongside one another on Earth. Eden trees use luminous lanternflowers to attract the creatures that help them reproduce, just as flowering plants on Earth use colour and scent. I gave a lot of thought to the biology of Eden, but I have to admit that, in strictly scientific terms, my imaginary world isn’t entirely viable. Free-floating planets with warm cores? Yes! Not just possible, but a certainty! But free-floating planets with warm surfaces? Sadly no. More than one astronomer has told me they just couldn’t happen. No matter how many radiator-like trees there might be, I’ve been told, it still wouldn’t be enough to maintain liquid water or a warm atmosphere. Let’s call it “fiction science”, science made up for a story, which works in some places and in others allows itself poetic licence. Almost all science fiction uses fiction science and Dark Eden contains several other examples. I took some liberties with human genetics, for instance. And then there’s the question of how people got to Eden in the first place. (It’s many light years away from Earth.) Like the writers of pretty much all stories set in interstellar space, I pretended that faster-than-light travel was possible and went with that, although it most probably isn’t. (I think that’s OK. It allows us to visit, in our imaginations at least, parts of the universe we could never otherwise hope to reach.) What I wanted from Eden was for it to be a world that hung together well enough to be a satisfying setting for my story, one in which I and my readers could immerse ourselves. The story is about exile and loss. The perpetually dark sky, and the animals with their blank unreadable eyes, serve as reminders that Eden folk are exiles. At the beginning of Dark Eden, every human being in Eden lives around a circle of stones that marks the place where their ancestors first touched down. And this circle represents to Eden folk the hope for return and redemption, which is central to their whole world view. The fact that I took some liberties when constructing Eden doesn’t mean it wouldn’t be interesting also to write about a real free-floating planet. And, as it happens, I’ve had the opportunity recently to do just that. In a project initiated by Comma Press, I was one of a number of writers who paired up with astronomers from Jodrell Bank to write stories for an anthology called Firmament. My astronomer collaborator, Ida Janiak, helped me build a scenario in which a free-floating planet called Lupus arrives in the solar system. Apart from being roughly Earth-sized, Lupus isn’t much like Eden, but somewhat like the Jovian moon Europa. Its surface is covered by a kilometres-thick shell of ice in no danger of melting, with a liquid ocean beneath and… well, read the story! The anthology will appear in November but there will also be a condensed version of mine and Ida’s story in the Christmas edition of New Scientist, out online on 16 December and in print on the 19th. I hope, meanwhile, you will immerse yourself in the luminous forests of Eden with their pulsing trees. Possible or not, they are very beautiful, if I say so myself. Dark Eden by Chris Beckett is the November read for the New Scientist Book Club. Sign up for the club here, and join the discussion on Discord here. When you make a purchase via the links on this page, we receive a commission.