Think of some famous outside-of-the-solar-system planets from say, Star Wars. Tatooine. Hoth.

They all have something in common: No matter where you land, the landscape is pretty much the same: on Tatooine it is a desert, possibly with some rocks; On Hoth it is all a frozen wasteland, with almost nightly blizards. It doesn't matter if you land on the pole or the equator, it is the same. However, on planet earth, we have locations where we can film all of thse planets, because of the diversity this planet.

Is it even possible to have such vast climatic zones, or is it just people being too lazy to create more ecosystems into their fictional worlds?


2 Answers 2


Yes, it is much harder to get Earth-like conditions than desert or ice

Desert planets have a much larger Goldilocks zone since, without so much water, they don't have the problem of icing up or a run away green house effect. This means desert planets could be much more likely homes for life. You would get some variation in temperature but there is no reason not to believe that it could be a desert all over the planet.

Similarly with an ice planet, once you've accepted ice on your planet there is a larger range of orbits your planet can have. Past a certain point the water will freeze up and lead to a positive feedback effect (more ice reflects more light back out and loses more heat, produces more ice..etc). The Earth has been through ice ages before but the surface area of the sea (where it is harder to form large ice sheets) was just too large for the ice age to last.

So both situations are possible, it would be much harder to suppose you had a precisely balanced ecosystem, like the rain forest or jungle, covering a whole planet from pole to pole. Ice and desert can, once they're in a certain temperature range, exist in a larger range of temperatures.

  • $\begingroup$ Of course, "jungle planets" also exist in sci-fi. But more importantly, while a life-bearing desert planet isn't impossible, it's a lot more implausible that you'd get a life-bearing desert planet that can support humans natively. Large swathes of time on Earth were inhospitable to humans - too much/little oxygen/carbon dioxide/methane/... and we evolved on Earth. A stable ecosystem on a "single-biome" planet may be possible (Snowball Earth arguably wasn't stable - it probably almost destroyed Earth life entirely), but that doesn't mean it will support humans. $\endgroup$
    – Luaan
    Commented May 16, 2017 at 13:56

According to some scientists, our planet has undergone a phase called "snowball planet" in its past, when all the planet was completely covered, from the poles to the equator, by a huge layer of snow and ice.

The initiation of a snowball Earth event would involve some initial cooling mechanism, which would result in an increase in Earth's coverage of snow and ice. The increase in Earth's coverage of snow and ice would in turn increase Earth's albedo, which would result in positive feedback for cooling. If enough snow and ice accumulates, run-away cooling would result. This positive feedback is facilitated by an equatorial continental distribution, which would allow ice to accumulate in the regions closer to the equator, where solar radiation is most direct.

So, in principle it can be possible.

Moreover, consider that movies like those you referred to are not focused on travelling the entire planet, therefore infering the planet climatology from them is like assuming all Earth is covered in skyscrapers just watching some Die Hard movies.

  • 2
    $\begingroup$ The opening crawl of Episode V literally describes Hoth as an "ice world". Episode IV has them fighting on the "forest moon" of Endor. I think we're pretty safe in surmising that the view is pretty much the same everywhere. $\endgroup$ Commented May 16, 2017 at 12:21
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    $\begingroup$ Snowball earth wasn't a real snowball but rather a mud- and waterball with some ice apparently. $\endgroup$
    – Raditz_35
    Commented May 16, 2017 at 12:47

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