For the longest time I’ve been under the impression that Jupiter was either 100% clouds or mostly clouds with a small, solid, Earthlike core. I know, it doesn’t make much sense, what with all the gravity and stuff.
After watching an episode of Cosmos, I now understand that the cloud layer is quite thin. But what’s the rest of it made of?
The gas planets do not have solid surfaces, their gaseous material simply gets denser with depth (the radii and diameters quoted for the planets are for levels corresponding to a pressure of 1 atmosphere). What we see when looking at these planets is the tops of clouds high in their atmospheres (slightly above the 1 atmosphere level).
Jupiter is about 90% hydrogen and 10% helium (by numbers of atoms, 75/25% by mass) with traces of methane, water, ammonia and “rock”. This is very close to the composition of the primordial Solar Nebula from which the entire solar system was formed.
Would you mind posting the link? I ask because most of this makes very little sense to me.
I would think that eventually you’d get to a point where gravity was pulling so hard that the gases would condense down to a liquid and, deeper still, a solid. In fact, this cite suggests that strange things happen in gas giant cores, like rocks and crystals behaving like metals:
I’ve heard the giant diamond theory proposed seriously, the thinking being that the carbon would settle to the center and become compressed into diamond. Has this been generally debunked, or was it never taken seriously to begin with?
The only place I’ve ever seen it proposed was in the novel 2061 and I don’t remember seeing it anywhere else. Clarke mentions an article in Nature called “Diamonds in the Sky?” from 1981. (This is according to Wikipedia, as I don’t remember all of this. The book is not really a great read.) I don’t have online full-text access to that year, but the article (as a letter to the editor) does in fact exist. I can print the abstract.
"Nature292, 435-436 (30 July 1981)
The ice layer in Uranus and Neptune—diamonds in the sky?
University of California, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
Many of the current models of Uranus and Neptune postulate a three-layer structure, consisting of an inner rocky core, a middle ‘ice’ layer of fluid, H2O, CH4, NH3 and an outer hydrogen−helium layer of solar composition. The estimated pressures and temperatures of the ice layer ranges from about 6Mbar and 7,000 K at the inner core-ice boundary, to approx0.2 Mbar and 2,200 K at the outer ice/hydrogen−helium boundary. I point out here that shockwave experiments on these liquids, as well as theoretical studies, imply that the H2O and NH3 in the ice layer are almost totally ionized and the CH4 has been pyrolysed to carbon, possibly in the metallic or diamond form."
I have no idea what happened either way with the idea.