I want to have an Earth like planet, but with most of the continents having very little flatland. Thus continents would be covered mostly by hills and mountains. I want the rest of the planet to be as similar to Earth as possible in size, gravity, ocean coverage, atmosphere, etc.

How do I explain this?

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    $\begingroup$ I know it's science based... BUUUT... "The creator is wise, the creator is generous, but the creator has great trouble unfolding things - and after precisely three attempts to shake the rug of the earth into flatness the almighty sighed, and decided it was a better thing to paint the stars instead. For the almighty loved creation unfairly, and loved nothing more than stars and beetles... post rationalising that the folds of the earth would of course best suit beetle kind." $\endgroup$
    – user20787
    Nov 18, 2016 at 22:19
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    $\begingroup$ Not to try to offend anyone here, but if you accept an answer right away within an hour, you might reduce the number of good ideas and discussion. You might consider waiting at least a day to pick your favorite answer. This is a pretty interesting question, and I'd certainly like to see more opinions. $\endgroup$
    – kingledion
    Nov 18, 2016 at 23:07
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    $\begingroup$ And here I was thinking that this question was going to be about Edwin Abbott Abbott's book! $\endgroup$
    – CJ Dennis
    Nov 19, 2016 at 3:29
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    $\begingroup$ How about cratering? Just make sure none of the impacts are big enough to make a sea of magma. $\endgroup$ Nov 19, 2016 at 8:38
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    $\begingroup$ See also worldbuilding.stackexchange.com/questions/36021/… $\endgroup$ Nov 19, 2016 at 8:41

5 Answers 5


That sort of terrain might come about as a result of this planet having many more tectonic plates than Earth.

For example, when the planet formed, these plates may have collided much more chaotically, and violently than Earth's, thus resulting in more mountain ranges than we have.

This will also result in a lot more volcanic and earthquake activity than Earth. These in turn can also shake the landscape up.

Add to this some meteor impacts in the distant past, and you're probably covered.

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    $\begingroup$ You will also need to have less of the precipitation that leads to the weathering/smoothing of Earth's geography. Which, given many coastal mountain ranges, you will likely get on the interior of continents. $\endgroup$
    – Samuel
    Nov 18, 2016 at 22:53
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    $\begingroup$ @Samuel Or rocks that are chemically and physically resistant to erosion. $\endgroup$ Nov 20, 2016 at 19:33
  • $\begingroup$ Make the planet younger than Earth, and erosion won't have smoothed things out as much either. $\endgroup$
    – Cody
    Nov 21, 2016 at 18:20

Give it smaller continental plates and speed up their movement. Mountains are raised where one plate pushes into another.

A lot of edges gives you a lot of territory that mountains are being created in.


A recent Snowball Earth period might help.

Heavy glaciation can cause enormous changes to the terrain. There are no longer any glaciers where I live, but there once were, during a recent ice age. Their legacy includes

The formation of glacial valleys in particular can be quite extreme:

Gif courtesy of Wikipedia user Intexpliki under the Creative Commons Attribution-Share Alike 4.0 International license.

You could go with a normal ice age, but you won't see glaciation over all of the planet, just portions extending out from the poles, perhaps into the southern temperate zones. That's why a Snowball Earth scenario is better.

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    $\begingroup$ This will also create plains. For instance, this is why northern Ohio is mostly flat. $\endgroup$
    – Samuel
    Nov 18, 2016 at 22:51

Make your planet younger than earth. Younger planets are more geologically active and have had less erosion - they will naturally be more mountainous/hilly. Though with some other more troublesome attributes to carefully manage in your story!

Evolution of Terrestrial Planet Surfaces

The link above discusses the effects of impact cratering, tectonic activity and then erosion during the evolution of a terrestrial planetary body's life cycle. In short - terrain will tend from geologically active and "rougher" to smoother less geologically active as a planet ages.

  • $\begingroup$ yes, thats what I was about to post, but you beat me to it. $\endgroup$
    – Jorge Aldo
    Nov 19, 2016 at 14:16
  • $\begingroup$ My bad - if you can make my answer better/fuller I'd appreciate any suggestions :-) $\endgroup$ Nov 19, 2016 at 14:23
  • $\begingroup$ oh I am not complaining, I upvoted your answer. $\endgroup$
    – Jorge Aldo
    Nov 19, 2016 at 14:27
  • $\begingroup$ How do I explain this (while, 'not explaining it at all')? Make the moon appear ~15 times larger than it does today, which would increase its gravitational pull by about 4k times (because it's closer). 'A young Earth', +1 $\endgroup$
    – Mazura
    Nov 20, 2016 at 19:58
  • $\begingroup$ An excellent solution @Mazura, ending up with an Io-esque situation where the increased gravity generated by the larger moon and more importantly it's orbit results in increased geological activity. See the section on Io here: astronomynotes.com/solarsys/s14.htm - You could achieve a similar effect (with many, many unintended side effects I'm sure) by making the current moon's orbit more eccentric and this changing the effect of it's gravity on earth, that said you may need a combination of the two! $\endgroup$ Nov 20, 2016 at 20:30

Well, I'm going to add an option: crust-buster bombs.

That's right, ladies and gentlemen, we've created weapons capable of simultaneously creating a hole from the surface to the mantle and the pressure waves necessary to trigger an instantaneous volcanic eruption through that same hole! Thanks to our new handwavium technology, this awesome force can be yours for the mere price of... (Terms and Conditions may apply, not guaranteed to work in areas with thicker-than-average crust such as existing hills and mountains.)

I'm sure you can find some sort of way to justify a world where people went crazy with the crust-busters and basically turned the entire planet into a series of volcanoes for a few months. Bam!!! No more flatlands.

If you want a more 'natural' explanation, I can't do better than Andrei.


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