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This page argues that Saturn's density tells scientists that it has a liquid metal core with maybe some rocky chunks:

The core region of Saturn may never be directly observed. Neither has the Earth’s. Despite that, scientists are fairly certain that, while Saturn has a core, it is not a solid mass of rock or metal, but a liquid metallic mixture similar to all of the gas giants.

Some, not all, Google image diagrams show a solid layer of ice around the cores of our gas giants:

Solid over liquidOnly gas over liquid

And this QA implies that that core would be completely covered by solid diamonds.

So, would there be anything solid to land on from the air inside Saturn, and what would that be?

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Cees Timmerman
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    Where does the thread you link to imply there's a core covered by solid diamonds? The theory about diamond precipitates (diamond rain in lay terms) suggests a dynamic process where at certain depth the pressure and temperature are sufficient for covalent bonds to form between carbon atoms. It also goes on to discuss that even those bonds aren't strong enough as they sink deeper and pressure further increases and that results in a carbon goo similar to tar. There's nothing like a solid surface on gas giants. Uranus and Neptune yes, to an extent with liberal definition, but they're ice giants. – TildalWave Mar 01 '15 at 13:16
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    If it helps add a perspective, see What will be the effect if we stand on Jupiter? Different gas giant tho. – TildalWave Mar 01 '15 at 13:26
  • The word 'ice' is not necessarily water ice; it may well be hydrocarbon ice/s. – Everyone Mar 01 '15 at 13:35
  • @Everyone Indeed, any volatiles with melting points above about 100 K are referred to as ices in planetary science. – TildalWave Mar 01 '15 at 13:48
  • @TidalWave I hadn't read the part about the diamonds being destroyed on the way down. – Cees Timmerman Mar 01 '15 at 14:02
  • I think the question needs to clarify just what is meant by 'core'. Taking Earth for example, you go through a layer of gas, probably a layer of liquid water, a rocky crust, (semi) solid mantle, liquid outer core, and solid inner core. Saturn probably has analogous layers on the way down: which one do you want? – jamesqf Mar 01 '15 at 19:45
  • @jamesqf As depicted, "core" means "center". I've specified gas-covered solid to land on. – Cees Timmerman Mar 02 '15 at 10:58
  • @Cees Timmerman: So as you go towards the center (in your unobtanium bathysphere) there might be a solid surface, or perhaps several, on the way down. But I don't think we have enough information to do more than informed speculation yet. – jamesqf Mar 02 '15 at 20:05
  • @jamesqf The rock and metal are probably molten at 12E3 K, even at 1.3E7 atm. Anyway, the Frenkel line (where gas turns to liquid) is way above that. – Cees Timmerman Mar 03 '15 at 09:22
  • Land on? I think that's impossible. The combination of heat and pressure would make it enormously difficult to descend more than a few thousand KM and even that would be enormously difficult. Any surface the planet might have is probably well below that. – userLTK Mar 25 '15 at 05:01

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No. The surface of Saturn is not solid. Saturn is too hot to support solid ice, and not just because of solar radiation:

Also like Jupiter, Saturn gives off almost twice as much energy as it receives from the Sun, because it has its own internal heat source, powered by the slow gravitational collapse that started when the planet first formed.

Given that Uranus and Neptune have an ice mantle, Saturn's sheer size and accretion must have extended the process.

Jupiter and Saturn have no ice mantle

Any solid ice present on Saturn is high up in the atmosphere or deep beneath dense liquid gas along with the other solids. Any diamonds created by atmospheric pressure would eventually melt into a liquid sea in the planet's hot core.

Shock wave experiment provides the best look yet at 'Warm dense matter' at cores of giant planets

Cees Timmerman
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  • "The surface of Saturn is liquid." Is this true? Is there a well defined surface, an interface between gas and liquid? Or is it a continuous gradient in density with no clear boundary? – uhoh Feb 27 '17 at 15:58
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    @uhoh As commented, the transition from gas to solid is the called the Frenkel line, not the Frenkel gradient. Above that is probably supercritical fluid, which is a gradient from gassy liquid (bottom) to liquidy gas (top). – Cees Timmerman Feb 27 '17 at 18:20
  • Ah, I missed the comment (it was hidden). But that's not what the Wikipedia article says at all. It does not say "where gas turns to liquid". Instead it describes a variety of alternative possible theoretical definitions, applied to theoretical models, and seem to be arbitrary thresholds applied specifically to smoothly varying parameters. A real gas to liquid transition takes place over deep sub-micron distances. These are smooth, gradual transitions, and the "line" is a mathematical construct. – uhoh Feb 27 '17 at 23:45
  • Not only a construct, but there isn't even one single, universally accepted way to define it: "There exist several approximate criteria to locate the Frenkel line on the pressure-temperature plane." – uhoh Feb 28 '17 at 00:09
  • Further, while another Wikipedia article about Saturn mentions the Frenkel line, its only in the introduction but not in the body, and the citation for that sentence (16) is from the Astrophysical Spectator a personal blog, not a peer reviewed journal. But neither that page, nor the entire blog contain "Frenkel" anywhere, so it's really unsupported.. Can you find some reliable scientific source to support "The surface of Saturn is liquid."? I don't think Saturn has a surface at all. – uhoh Feb 28 '17 at 00:09
  • "At high pressure and temperatures, metallic hydrogen might exist as a liquid rather than a solid, and researchers think it is present in large amounts in the hot and gravitationally compressed interiors of Jupiter, Saturn, and in some extrasolar planets." - Wikipedia on ISBN 0-521-81808-7 – Cees Timmerman Feb 28 '17 at 11:38
  • I'm not sure I understand the relevance. I'm just asking "The surface of Saturn is liquid." Is this true? I'm just asking about the "surface of Saturn" being 1) clearly defined at all, and 2) a boundary between (presumably) gas and liquid. Maybe there is liquid metallic hydrogen in Saturn. It's proposed, it's probable, but it is still just an educated guess. But that doesn't mean Saturn has a well defined surface. It might not actually have a well defined surface at all. You might consider adjusting your first sentence. Perhaps "If saturn has a well defined surface, it would be..." – uhoh Feb 28 '17 at 16:15
  • http://www.space.com/18472-what-is-saturn-made-of.html "Saturn is classified as a gas giant because it is almost completely made of gas. Its atmosphere bleeds into its 'surface' with little distinction. If a spacecraft attempted to touch down on Saturn, it would never find solid ground... Because Saturn lacks a traditional ground, scientists consider the surface of the planet to begin when the pressure exceeds one bar, the approximate pressure at sea level on Earth." There is more to read there than I can quote here. – uhoh Feb 28 '17 at 16:23
  • I define "surface" as "where the gas layer ends" and would like the official source and reason of the "over one bar" definition. – Cees Timmerman Mar 01 '17 at 18:51
  • OK but 1 bar = 1 Earth Atmosphere of pressure. That's closer to where the atmosphere begins than where it ends. It's way up at the top, roughly where the visible outer edge of the planet is; there is still gas way deeper than the 1 bar point. – uhoh Mar 01 '17 at 21:58
  • And using that alleged definition of "surface" on Mars, you'd have to dig before reaching it. – Cees Timmerman Mar 01 '17 at 22:10
  • It's a working definition - meaning it is used in order to get some work done - a practical definition. There are many places where you have to use some number for the radius (like animations, non-precision occultation timings...) and it is only used for the four gas giant planets Jupiter, Saturn Uranus, and Neptune. Thanks for the edit, +1, and thanks for the fun conversation! – uhoh Mar 01 '17 at 22:30
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It is worth emphasizing what was mentioned in the comments to another question - all the outer planets have atmospheres that gradually transition from gas to supercritical fluid. There is no ocean of liquid hydrogen on Saturn that you could float a boat on. It just gets denser and denser and hotter and hotter until your space probe is crushed or melted, whichever comes first.

And the layers of ice aren't frozen either. Basically the term "ice" refers to anything that would be frozen if it were on the surface of an outer-planet moon.

Mark Foskey
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