A large planet roughly 3-4 times the mass of Earth. Trying to keep Gravity between 0.75G-1.25G for Earth-like Conditions.

I've looked into certain materials such as Silicon Carbide, which is reasonably light and mostly incompressible. Which is rare on Earth, yet common in space. Could a planet form with a large mass of Silicon Carbide without having the downsides of being a Carbon world? (I.e lack of water on the surface)

  • $\begingroup$ Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. $\endgroup$
    – Community Bot
    Commented Oct 10, 2023 at 11:05
  • $\begingroup$ In my simulator best candidate of earth-like planet of 3.6 earth masses has 1,69 earth's G and quite dense atmosphere of 2.4 of earth's (but this is second derivative parameter). The planet has enough metals to be not pure rocky one, so there's a magnetic field, water and so on. Don't know the compound but it's all based on meticulous physical formulas. The density 6.3 - I struggle to generate below 5.5 g/cm3 - don't remember why, but it was due to some gravity infridgements. Hope this help a bit. $\endgroup$
    – Peter.k
    Commented Oct 19, 2023 at 21:12

1 Answer 1


While this is possible (albeit quite unlikely), a silicon carbide world may not be habitable to life (as we know it). According to this paper, a lot of CH4 and H2 would be produced in the presence of water in the crust, hence likely forming a thick and dense atmosphere of reducing gases. So definitely not earth-like. However, if the temperatures and pressures are right, you could potentially have lakes of liquid methane and maybe have life based of different biochemistry (think of methane or silicon based life), and maybe have a cool looking shiny diamond planet!

  • $\begingroup$ This is very helpful! Potentially to make things more Earth-like perhaps some Microorganism could consume the Methane, and if over a long enough timescale enough Silicon Carbide is converted to Diamond the planet could become similar to Earth on the surface, while retaining a low density. $\endgroup$
    – Spoon
    Commented Oct 10, 2023 at 20:37

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