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dickbutt_md t1_j5lxryj wrote

Reply to comment by MsGorteck in Have you ever thought about what it sounds on jupiter by Western_Home6746

I feel like no one in this thread knows that Jupiter doesn't have a surface.

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DukeElliot t1_j5m0qn8 wrote

Sounds like the jury is still out on a solid surface https://www.space.com/18388-what-is-jupiter-made-of.html

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dickbutt_md t1_j5m2vb1 wrote

I wouldn't consider a solid core to be a solid surface, though.

This is a semantic distinction, though, at this point we would be arguing about what to call whatever is there, not a disagreement about what is actually there.

Though I'd prefer to distinguish between the core and the "surface" such as it is, I do think there's a reasonable argument to be made that "surface" should be identified as "whatever is solid." The problem with this terminology is that it doesn't really recognize any difference between gas giants and rocky planets, which I'd argue is a useful thing to do.

But, when it comes to what's actually there, I think we agree.

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DukeElliot t1_j5mbi1e wrote

There is a sentence in that article that says “While some theorize that the core is a hot molten ball of liquid, other research indicates that it could be a solid rock 14 to 18 times the mass of the Earth” referring to the core

Would “solid rock” not mean a solid surface in this context?

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Bipogram t1_j5mhk4m wrote

Over which is an ocean of hypercompressed hydrogen at essentially the same density as the rock below.

The only transition is one of composition (mumble: and both seismic speeds) rather than density - which we seen in the terrestrial oceans.

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ghostoftheai t1_j5neitn wrote

So if it’s as dense as rock can you walk on it or is that not how it works?

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Bipogram t1_j5p5m64 wrote

We can walk on things because they're rigid solids.

But I doubt that there's a nicely defined discontinuity between the metallic hydrogen ocean and some rock.

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dickbutt_md t1_j5nsyid wrote

The surface of a gas giant is defined separately from the core, as the article says: "...there is no solid ground, the surface of Jupiter is defined as the point where the atmospheric pressure is equal to that of Earth."

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MsGorteck t1_j5lz950 wrote

So the metors that plowed into Jupiter years ago just went through? I thought, while small, that in the center there would be a solid something. Not big, because of all the weight and pressure, but something.

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Bipogram t1_j5m1naw wrote

No - they didn't "just go through" - they encountered gas that became increasingly denser as one sinks into Jupiter.

There probably is a solid core of rock, but before then you encounter multi-bar pressures, and densities exceeding that of common fluids here.

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decomposition_ t1_j5pav9n wrote

I wonder if there are layers before the core that have some amounts of solids settled in above higher density gases. So not that it’s a surface but that it’s a layer of solid (even if it’s a dusty consistency) above denser gases

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Bipogram t1_j5pdgoh wrote

Here are some of the best models we have of Jupiter's near-core:

https://arxiv.org/pdf/1812.07436.pdf

p12 allows for both a sharp discontinuity and a gradual 'fade' from metallic hydrogen to rock. The data we have cannot distinguish between those models.

"The existence of a diluted core, or a steep heavy-element gradient inside Jupiter is actually consistent with formation models of Jupiter (see section 4.3 for details). Giant planet formation models in the core accretion scenario (e.g., Pollack et al., 1996) suggest that once the core mass reaches ∼ 1 − 2M⊕ the accreted solid material (heavy elements) vaporise and remain in the planetary envelope (e.g., Stevenson, 1982). This leads to a structure in which the deep interior is highly enriched with heavy-elements, with no sharp transition between the core and the inner envelope (e.g., Helled & Stevenson, 2017 and references therein)."

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