I won't describe in much detail the geology and astronomy of the world I'm creating here, whose unnatural shape and so far unexplained non-Einsteinian large-scale mechanics to maintain it may not be truly relevant (and I could ask about in another question).

Suffice to say, in this world, you have extremely slow seasonal changes with one cycle lasting about ten thousands years, give or take one or two millennia. During the winter, there is no sunlight of the surface at all and during the millennia before and after, very little sunlight. Note the duration of the winter can be adjusted, but we'd like it to be superior to 400 years long.

The world has some negative curvature, and in such places, you can see part of the distant world in the night sky. Also, the cold winter seas are often connected to warm summer oceans, being a big body of water exposed to the sun or not by two different surfaces.

What strategies could an ecosystem use to live through the winter? By "survive", I do not mean "preserve". A large part of the life can die off. But some portion of it would be able to seasonally adapt to the winter until the spring. A sub-portion need not to be active during winter, just be ready to bloom/hatch/awaken in the spring.

Note: this is similar to this question, How could a small fantasy world survive hundreds of years of darkness?, but I'm asking in a general non-fantasy-magic setting for the entire ecosystem (but not 100% accurate to reality).

  • 1
    $\begingroup$ Your asking 2 questions here, one about how life can survive and 1 about how a human tribe can survive, please split the 2nd question to it's own question. $\endgroup$
    – cypher
    Commented Jul 26, 2018 at 20:06
  • $\begingroup$ Welcome to Worldbuilding.SE! We're glad you could join us! When you have a moment, please click here to learn more about our culture and take our tour. Thanks! $\endgroup$
    – JBH
    Commented Jul 27, 2018 at 5:13
  • $\begingroup$ You've already come up with a substantial list of possibilities. Our help center states you should avoid questions where "your answer is provided along with the question, and you expect more answers." $\endgroup$
    – JBH
    Commented Jul 27, 2018 at 5:16
  • $\begingroup$ I've cut off pagraphas the question to remove my (unsatisfying) answers and the secondary question. Should I trim more to avoid to get "too broad" ? $\endgroup$
    – Lærne
    Commented Jul 27, 2018 at 13:30
  • $\begingroup$ This is in the VTR queue, but I can't vote to reopen it because commenting on "the entire ecosystem" is still too broad. Do you really want to know about how the bacteria Streptococcus mutans would fare? It would take volumes to answer such a question. Please narrow this down (a lot). $\endgroup$
    – JBH
    Commented Aug 2, 2018 at 3:17

3 Answers 3


tl;dr: Make it so the people are nomadic, moving along the terminator line between the day and night side. Plants grow along the edge between day and night, and move with the line as well. So do animals.

Eyeball Earth

You shouldn't be asking how people can possibly live in a ten-thousand year winter, you should be asking what it takes to live in a ten-thousand year summer! Ten thousand years of direct sunlight will surely scorch the land that they are living on! So instead, have the human tribes be nomads walking just behind the terminator line for the night side, maybe 10-20 years of rotation away.

As the terminator moves forward, it exposes icy areas to the sunlight. After a few years, the ice thaws and the plants move in, probably by seeds blown in by the wind. A few years after that, the animals and humans come in after the plants.

I'll do some math just because this is fun. Say we have an earth-size planet, 7000 kilometers in diameter. For it to make one full revolution in ten thousand years, the planet needs to spin at circumference/10000 years speed, or (43982.2971503 km)/(10000 yr) = ~4.3 km/yr. That's ~11.7 meters/day. Humans, plants, animals can definitely keep up with that. At higher latitudes, this number is even smaller (~5.8 m/day at 60N, ~0.2 m/day at 89N), which might mean that people could start agriculture due to the slower spin.

  • $\begingroup$ Would you add a source for your image please? It looks like something real. $\endgroup$
    – Willk
    Commented Jul 26, 2018 at 23:25
  • $\begingroup$ I'm not entirely sure that there is a terminator in this scenario. From the sounds of the question, it looks like the entire planet is bathed in darkness $\endgroup$ Commented Jul 27, 2018 at 0:33
  • $\begingroup$ @Willk it is an artistic interpretation. Source is NASA I think $\endgroup$ Commented Jul 27, 2018 at 3:30

Whale fall.

A whale fall is the carcass of a cetacean that has fallen into the bathyal or abyssal zone (i.e. deeper than 1,000 m, or 3,300 ft) on the ocean floor.[2] They can create complex localized ecosystems that supply sustenance to deep-sea organisms for decades.

whale fall

On your world, there are huge creatures far above. They accumulate energy and nutrients over the centuries as they traverse the upper atmosphere and interplanetary spaces, absorbing light and stellar wind. Sometimes these creatures come down - maybe because they die, or beach themselves on the surface, or because it is part of their life cycle. When they do they provide an island of concentrated resources for the night planet, much as a whale fall provides nutrients for the creatures from the abyss.

The humans have ways of identifying a whale fall from afar and stake it out, defending it from other denizens of the night planet.

Maybe sometimes these fallen star whales live for a while on the surface. They might have something to say to the humans. Or maybe they sing as they die.


What your basically asking is what other forms of energy can be used to sustain life for those "dark periods", I have a few possible ideas based on RL animals & planets who live in areas of the planet who never see sunlight:

  1. There are large ecosystems living in parts of the ocean so deep that they never see sunlight around hydrothermal vents, the heat and pressure will prevent the water from freezing over and will allow a ecosystems very much like those living around them on earth to exist on your world (never ending darkness is the same, and water is the same regardless of what planet your on or what shape it is).
  2. Extremophiles can live in conditions that are quite frankly insane, some can live around nuclear sources and feed off radiation (which also gives off heat and light regardless of having no sunlight).

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