What would be the best place to put a colony on an extrasolar planet?

This planet is earth-like, about the same age, and has sturdy trees that can be made into houses (demonstrated by the two people sent out to catalog the life and other science things there). There are 500 people on this colony ship, and they will be transported down to the surface by the extremely large colony ship aerobraking. As materials can be obtained from asteroids, the main resources being required would be food, through agriculture, and wood, through sustainable nearby logging.

The planet has no predators more dangerous than what we have here, and generally in the same population. Nothing that can't be kept out by a wooden or chainlink fence. A river is only optional, it would just be aesthetic. The environment would have to be temperate, so no really hot and humid environments.

Energy can be obtained from either reactors or solar panels, so energy isn't a problem.

Edit: Essentially, what other factors should be considered when placing a colony?

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    $\begingroup$ I like your question. +1. $\endgroup$
    – Ender Look
    Dec 9, 2017 at 1:20
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    $\begingroup$ How are we supposed to answer this with any more detail than saying "Putting it on the surface would be best."? Questions on this site should be answerable. $\endgroup$
    – sphennings
    Dec 9, 2017 at 1:31
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    $\begingroup$ There isn't enough information to answer this question. For example, if you asked about Mars, I could say you could land on Tharsis because of reason X, or you should settle in the south facing rim of Hellas because of Y. But reasons X and Y come from detailed knowledge of the geology and terrain of Mars. I don't have any such knowledge of your planet, and there isn't enough space to provide it. Therefore, a question in this form is primarily opinion based and isn't a good fit for this forum. $\endgroup$
    – kingledion
    Dec 9, 2017 at 1:47
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    $\begingroup$ I believe the Asker is attempting to ask what factors should be considered when choosing a colony site on an earth analog extrasolar planet. $\endgroup$
    – Stephan
    Dec 9, 2017 at 2:04
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    $\begingroup$ @Stephan Then the question should be edited to reflect this. $\endgroup$
    – sphennings
    Dec 9, 2017 at 2:23

3 Answers 3


When choosing a colony site on any planet, 3 factors tend to play a major role.

First is accessibility to supply lines, access to resources, and shelter from extreme weather.

For a space colony, the supply lines are from orbit. This is most energy efficient along the rotational equator. So any landmass near the equator will have a higher weight.

For resources, food, water, and shelter are most important. If the colony world has edible fish analogs, any landmass near the equator, that's also near a body of water moves up the roster for candidate sites. Access to forest land further narrows the selection.

Finally, building on the lee side of a mountain or range of hills will help protect from the prevalent weather patterns. Likewise avoiding flood zones and other recurring natural disaster zones will also be favorable.

To summarize, you're looking for equatorial, temperate, forest land near a river, lake, or ocean with solid ground that's sheltered by hills or mountains.


Larry Niven pointed out long ago that in order to travel space (without a lot of handwavium), you need to have already solved the problems of food and habitat and energy and sociology, etc., that make the colony on the far side challenging [1].

In other worlds, where do we put the colony? In orbit. Most natural place for colonists who spent years (or generations) in a habitat traveling there. I don't know how our descendants solved food/water/shelter and other needs...but they did or they wouldn't be there. Let's say they harvest comets and asteroids. Sure.

Are there likely to be planetary installations? Yes. Think along the lines of oil-drilling platforms: Work environments. Research camps. Support infrastructure.

Groundhog colonies are likeliest to initially grow from three sources:

  • Adjacent to existing ground installations or re-use of installation infrastructure
  • Tourist attractions
  • Ground facilities that produce goods and services for the other two

Humans are already very good at food/water/shelter in inhospitable climates (We built huge coastal cities in Florida, for goodness sake!). Humans are also quite good at adapting to the resources at hand, and trading.

While the initial colony will be in space, ground colonies seem likely to (slowly) follow.

[1] Larry Niven, A Hole In Space, 1974

  • $\begingroup$ A problem with space colonies is mental health. $\endgroup$
    – GoingFTL
    Dec 9, 2017 at 22:10
  • $\begingroup$ Addressed in the first paragraph. $\endgroup$
    – user535733
    Dec 14, 2017 at 19:22

Well, this is primarily bounded by the technology of these people, and there are a few potential circumstances.

Though, you say that materials can be attained from asteroids. If we can get materials from asteroids, then that assumes we can get back off the surface of the planet easily. If we can do that, then it should be even easier to move around the surface of the planet. In such a circumstance, they could potentially land anywhere and just use their vehicles to get to the place that they need to be.

If we assume the circumstance that, once they land, they will have to stay in the place where they landed for a good deal of time, then that makes the question a little more complicated. First off, what are the bounds of their space flight before they land? What angles are they coming in from? Do they have excess fuel to burn? Are they intending to make several passes before actually landing? What kind of optics do they have? Can they observe the surface of the planet weeks in advance?

Let's suppose that we have the worst case scenario. The ship only has optics powerful enough to observe the surface from a short distance and the colony ship will be landing on the first approach to the planet. In such a situation, they need to evaluate their potential landing spots very quickly, which means they will favor spots they can see early on. They will aim for continents as they will be the largest targets. They will try and get close to the coastline, as there are various benefits to doing so. They would also favor landing around 45° latitude, as that is going to be the best region for temperature. They might also try and see if they can get near the mouth of a river, but it would have to be a very large river for them to have spotted it from space.

  • $\begingroup$ This answer seems to be mostly composed of questions. -1 $\endgroup$
    – kingledion
    Dec 9, 2017 at 1:54
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    $\begingroup$ @kingledion Conjectures rather than questions. More pondering the variables and possibilities that might be involved than actually asking questions. $\endgroup$
    – a4android
    Dec 9, 2017 at 5:53

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