Inspired by The One Million Earth Solar System.

A civilization wants to create a solar system with a lot of earth-sized planets. How would they go about building it? Specifically, how would they move planets to the new solar system?

  • There are no planets in the system
  • The civilization has plenty of planets but they are all in different systems
  • The civilization has FTL travel, and can build very large starships if needed
  • The price of FTL is based on the mass of the object being transported

What would be the best way to transport the planets, as small payloads, pre-assembled or whole planets?

How to move many planets, possibly up to one million of them, to the new solar system?

  • $\begingroup$ If they have FTL, why would they move material to this system instead of terraforming planets in place? You would need an incredibly good reason for such a massive (almost unfathomable) economic price. $\endgroup$ Jul 26, 2018 at 18:16
  • $\begingroup$ @GrandmasterB the context isn't important, I just want to know how this could be done. $\endgroup$
    – Starpilot
    Jul 26, 2018 at 18:17
  • $\begingroup$ @JThomas it is possible, actually. They could act as a ring, if they have a massive enough primary. See The Million Earth Solar System $\endgroup$
    – Rafael
    Jul 26, 2018 at 18:56
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    $\begingroup$ All of your questions are impossible to answer. You are actually asking people to tell you how they would do things some of which we actually think are impossible and way beyond our engineering and physics to the point it is pure fantasy. $\endgroup$ Jul 26, 2018 at 19:07
  • $\begingroup$ So I took the risk of editing the question. Roll back the edits if you disapprove. $\endgroup$
    – Vincent
    Jul 27, 2018 at 2:08

1 Answer 1


I think you'd well served by pulling all that matter together with a big artificial gravity generator. It would take time to get into one place and would weigh three or so times more than the sun but if you want to build earthlike worlds there won't be enough free hydrogen to start or support fusion so while it will get awfully hot it won't go stellar. It probably doesn't quite weigh enough to cause matter degeneration either.

So having put it all in the system you want to use you now cut it up into planet sized chunks using localised artificial gravity fields to pull masses off the huge matter reserve. Volatiles like water and atmospheric gases are going to be a major issue to balance and getting the planets to differentiate the way Earth has so that they're geologically functional is going to be even worse but this is an exercise is supertech so you'll manage.

The amount of energy you'd need for such an undertaking will require the direct and complete matter-energy conversion of a number of stars but by the time you're ready to try this kind of thing you'll have to be able to do that easily.

Do note I have assumed that you have millions of years to finish this project, I can see no feasible way to do this in a hurry.


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