I have this planet that's 1.8 times the size of Earth on an eccentric orbit around a star that's 0.2 times the size of the sun. Its apses often change due to the influence of a neighboring gas giant. At apoapsis, the entire planet is covered in oceans with only the highest peaks poking out as tiny islands and a small continent. At periapsis the entire ocean is reduced to a flat dry land. All of this cycle within the planet's year of about 10 days. The surface temperature can range from about 72.1°C to 416°C.

Could complex life develop here? I was thinking of some kind of fish that can burrow deep underground and emerge during the wet season.

  • $\begingroup$ You're asking two (already rather substancial) questions. I suggest in order to avoid getting closed for being too broad you limit yourself to one here and ask the other in a seperate post. $\endgroup$
    – AngelPray
    Sep 24, 2017 at 10:04
  • $\begingroup$ Welcome to Worldbuilding.SE one I'd suggest taking the tour it's worth your time as are the guidelines provided in the help section on how and what to ask about. In this case this question is very broad and a little unclear, I'd suggest paring it down to a single issue that you ask about in detail. $\endgroup$
    – Ash
    Sep 24, 2017 at 10:29
  • $\begingroup$ Let me just clarify that point, the planet goes from being covered in oceans with only the “highest peaks” showing to being covered in steam and back again every ten days? $\endgroup$
    – Slarty
    Sep 24, 2017 at 11:05
  • $\begingroup$ @Slarty "highest" would be relative. I haven't decided the height of the land and depth of the oceans yet. $\endgroup$
    – JPrescott
    Sep 24, 2017 at 11:55

1 Answer 1


Forget the hottest temperature even at the "cool" 72°C I can't think of any multi-cellular organism that can survive ongoing exposure to temperatures anywhere near that high, maybe some of the extremophiles from the deep sea thermal vents but maybe not even them. Certainly not a human, you'd start to literally melt after a few minutes. The main thing to my mind would be lack of food, any multicellular life on such a world would either be down deep in the water column were it stays cool or buried deep in the mud of the dry season where the sun never penetrates so surface food at any time of year is going to be next to nonexistent.

You could have life on such a world but it would be in the deep water and buried deep in the mud where the water never evaporated off or it would cook come summer.

As a note that's a pretty small Red Dwarf it's orbiting so radiation poisoning is going to be a concern since the planet will be tucked up pretty close to it's primary even at apses.

  • $\begingroup$ Gotta agree. Safest way to evolve here is deep in the ground. $\endgroup$
    – Joe Bloggs
    Sep 24, 2017 at 11:20

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