I think we’d find that a combination of gravity and pressure produce a very nice “virtual” container. In stead of thinking of the atmosphere pressing against the planet surface as a limit, think instead of gravity and the volume of atmosphere as producing a shell instead. In fact, you could consider it in terms of three rotations. 1) that of the planet surface 2) the different rotation rate of gas moving around the same axis of rotation and 3) the effectively “non-rotating” limit presented by attenuation of atmosphere and Saturn’s gravity.

Might be an opportunity for some fluid physicist to see what patterns emerge in a fluid when you have a sphere rotating within a second sphere, with the fluid sandwiched between them.

Emily’s hesitation whether or not the bucket experiments is applicable to Saturn’s stable hexagon because the planet “has no edges” can be argued as follows. The first to study mathematically the problem with an arbitrary number of polygon sides was J.J. Thomson [Treatise on Vortex Rings (Macmillan, London, 1883), p. 94]. Havelock [Philos. Mag. 11, 1931, 617] generalized Thomson’s treatment including also (among other things) an external confining wall. His analytical results indicated that besides the heptagon (N = 7), an external retaining wall is not expected to change the ‘quality’ of the rest of the N-gons. Furthermore, based on the work of Polvani et al. [J. Fluid Mech. 255, 1993, 35-64] we can also conclude that the planetary curvature is not anticipated to affect the basic features of the event either.

But it certainly does seem like various pressure regions could serve the purpose of generating the same effects that a beaker-wall serves in the lab.

Or it’s a very big Carbon molecule.

I wonder what it is about our brains that assume things like that have to be messed with by something outside natural forces?

Well, Saturn is a gas planet, You would expect gas plantets to have a swirl. Yes, A lot of things in nature are geometric, I agree, but in this particular case, it is interesting, because it has been going on for a while(I think at least 30 years) and it’s on a different planet made of gases

By my calculations, that makes the area of the hex a little under 500 billion km². (494,777,633.69 km²)

Which makes it… almost exactly the same size as the surface area of the Earth, at 510,065,600 km². (Just 3% variance.)

Pretty cool coincidence! (Unless my math is wrong…)

GAry 7

I do love posts like this – things I wouldn’t have come across on my own but that are fascinating to me.

It’ll be interesting to see if it’s still there in another 20 or so years… when it was noticed in ’80 and ’81, was it the same season at Saturn’s north pole? I would think that if it was noticed in different seasons, that would support a conjecture that it’s always there…

Yes it oviously something sinister about to happen. Always nice to hear from the
CtC science advisor.

Ger

As the Sun cools off, it would radiate less, and so takes longer to cool off more. Once if got down to Jupiter’s temperature, it would take just as long to cool further. In fact, it would take an infinite amount of time to reach absolute 0, just like any other body. (This doesn’t happen in real life because any object is exposed to external heat, such as Jupiter and Saturn being warmed by the Sun in addition to their residual internal heat of formation, which makes computing their temperature as a function of time more complicated.)

I think when people say “Without internal fusion (or some other energy source) to keep it warm, the Sun would cool off in a million years”, they mean “cool off to room temperature”. It wouldn’t stop there, though. It would keep cooling off (at a slower and slower rate) forever. Jupiter and Saturn are already well below room temperature (after 4 billion years) and are continuing to cool. (Actually, Jupiter is. I’m not sure about whether Saturn is still cooling off or if it has reached equilibrium. I could look it up, but I’ve already googled one thing for this post (couldn’t remember the name of the Stefan-Boltzmann law), and that’s enough for one day

Also, you may wish to scroll up & down the page I linked to for other planets & moons.

Here’s an example of Jupiter: http://www.windows.ucar.edu/tour/link=/jupiter/images/interior_image.html&edu=elem