At a time far in the future, humanity has long expanded past Earth into nearby planets and solar systems. The planet in question was heavily used for it's resources to supply other planets who's resources were beginning to run out. Eventually, conversationalists heard of it's existence and protested the abuse of the planet and it's life forms and, consequentially, it was abandoned soon after. Years later, the interplanetary government decides upon a different way to use the planet.

The planet is hollowed out as best as can be without coming too close to the core or too close for the machines needed to melt. To replace the massive amounts of resources taken, it's replaced with technology. Eventually the massive internal cavern has transformed into a futuristic hub of activity, known for both fair trade and corruption. The living structures resemble stalactites, spiking from both the bottom and top of the cavern. For reference, It looks somewhat similar to civilization in the Altered Carbon series.

I originally planned for the planet to be completely split in half in order for it to be accessible from the outside, but I believe simply hollowing it out and leaving few ports of entry with high security is a better option.

My question is: Is a sustainable colony possible in a hollowed planet like mine? How would life there be any different than life on the outside of a planet?

Science and logic based answers please, I'd like this to be as realistic as possible.

  • $\begingroup$ you want a hollow sphere, in no way connected to inner sphere? $\endgroup$
    – Mołot
    May 21 '18 at 21:22
  • $\begingroup$ Do you want this to be hard-science or science-based? Two very different things, but your "realistic as possible" would better fit hard-science. $\endgroup$ May 21 '18 at 21:29
  • $\begingroup$ @Molot The planet is mostly hollow, not completely. The two are connected. $\endgroup$
    – Mop
    May 21 '18 at 21:33
  • $\begingroup$ We've had a lot of questions about hollow planets and I think a search would find you more than enough material to answer your question. $\endgroup$
    – StephenG
    May 22 '18 at 0:33

From OP

The planet is hollowed out as best as can be without coming too close to the core or too close for the machines needed to melt.

People do this on earth. It is called mining.


The mine is so deep that temperatures in the mine can rise to life-threatening levels. Air-conditioning equipment is used to cool the mine from 55 °C (131 °F) down to a more tolerable 28 °C (82 °F). The rock face temperature reaches 60 °C (140 °F).

Compared to the thickness of the crust, this 2 km mine is not that deep. And then there is the mantle and the core. Because you are concerned about heat and melting machines I conclude your planet is hot like Earth. An excavation of this sort cannot really be considered hollowing out the planet.

Your tech hub would be a bunch of artificial caves. Which is a doable deal. I wonder how exclusively living in caves is a good thing on a planet that can support life, but maybe that is where the story is.

  • $\begingroup$ a km or two all the way around would still be a lot of living space, but that's a chosen mine, some places have that kind of temperature at the surface. $\endgroup$
    – user25818
    May 21 '18 at 23:16

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