A hex on Saturn

By Phil Plait | April 3, 2007 12:46 pm

So by now you’ve seen the hexagon on Saturn’s north pole. This kind of news always seems to come out when I’m away from home and can’t spend time to write about it! Well, not always, but a lot. Or sometimes. OK, just this once.

But I’ll be lazy anyway, and point y’all once again to Emily, who has an excellent post about this.

Comments (38)

  1. Josie

    I always think it’s funny when people see something with angles, and assume it has to be ‘unnatural’ in some way. Haven’t these people ever looked at a bee’s hive, or a sunflower?

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

  2. baric

    I didn’t see a place to comment on the other blog, so I’ll comment here.

    It was suggested that the study involved rotating fluids within a container was not applicable to Saturn because the planet has “no edges” of an containing structure.

    I disagree and see relevance. What is happening is the result of the circular structure of the rotating fluid (forced outward by angular momentum created by the rotation) collapsing against the turbulence caused by an outer barrier.

    In the experiment, the outer barrier was the walls of the container. On Saturn, the outer barrier is Saturn’s immense gravitational field. Considering the rapid rotation on Saturn (12 hours?), its huge size and low density, we are basically seeing the outer atmosphere sloshing against the planet’s gravity.

    I am not a scientist. That is my layman’s analysis.

  3. Mark Martin

    The nature of the giant hexagon is quite simple. The formation is a super-colony of the Andromeda organism. Saturn is its home planet.

  4. John Powell

    My guess is that Saturn has a denser core that is rotating faster than the cloud layers above, and so is producing this hexagonal artifact in a an analougous way as the folks saw with the rotating plate in the cylinder.

  5. MKR

    I guess I should pack my bags. The aliens will be here to pick us up soon.

  6. tacitus

    Hexagons on Saturn?? If that doesn’t prove hyperdimensional physics is true, nothing will!

  7. tacitus

    Old Hoagie’s getting excited with “Major Paper to be Published Soon” posted on his website. That, and a message about Pluto Express passing Jupiter are about the only new thing he’s posted there in years. Must be hot news indeed…. or maybe just another rambling monologue about how he was right all along.

  8. spacewriter

    Hm, this is jogging a memory of a planetary science atmospheres experiment we did back a few billion years ago when I was in grad school… we heated some oil in something shaped like a pie plate and I believe we had another fluid of a different viscosity in there, too. The heating from the hot plate below caused a similar-looking pattern to form in the material at the center, and it seemed to be ‘bound’ in place by the surrounding material… darned if I can remember what the point of the experiment was now…

    {wanders off to look for old college notes…}

  9. I’m still perplexed by the fact that the Jovians are exothermic.

    I remember Phil saying in a Q&BA that an object the size and temperature of the sun would radiate off all its energy in about one million years if not for the internal fusion. Why then have the Jovian worlds not radiated away all of their original energy?

    Maybe I’m missing something. I’m not an astronomer.


    Thabks for posting this. I’d heard about it, briefly, on the news, but it was quickly swept away by the latest reports about American Idol and the Anna Nicole Smith saga.

  11. I was going to post about some experiments done where they made polygons in rotating fluid, but it appears Emily has already done so.

    My only concern about these sorts of discoveries is that they fuel yahooery like that TimeCube guy who, right now, is likely working on the Time Hexagon… er maybe not since a cube has 6 faces.

    here’s an astronomy question, and it’s lame, so excuse me please, but I can’t find the answer so I must be lookign in the wrong places… I’d like to find something that discussses the make-up of Saturn and/or Jupiter. Like a cut-away diagram that explains the structure. Even better would be such information for all four outer planets.

    If someone has a good link to such a thing, I’d be grateful if you could post it or send it to me.


  12. pgdunne

    Have you tried Wikipedia? Eg, Google {wikipedia jupiter}

  13. Melusine

    Evolving Squid, do a Google image search for “Jupiter schematic” or “Saturn schematic.” There are lots. NASA has both.

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

  14. Melusine

    Sorry for the messy link above. Evolving Squid, do a Google image search with “cutaway,” too. Like this: Jupiter and moons. Then do the same for Saturn.

  15. CR

    Don’t know if this;ll help, Evolving Squid, but here are some handy, basic PDFs you might be interested in. http://www.eso.org/outreach/eduoff/edu-materials/info-solsys/eng/index.html#jupiter-eng

  16. CR

    Grr, I wish this blog had a preview function…
    Anyway, “this;ll” should have read “this’ll” in case it wasn’t obvious.

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

  17. Buzz Parsec

    Thomas – The Sun, without fusion to keep it warm would cool off much more quickly than Jupiter or Saturn because objects radiate heat proportional to the
    4th power of their temperature (the Stefan-Boltzmann Law), and the Sun is about 30 times as hot as they are.

    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 :-)

  18. I though it was the head of the big bolt that is holding Saturn together!
    Can you imagine the size of the socket wrench?!?! =-)

  19. gerald miller

    “Old Hoagie’s getting excited with “Major Paper to be Published Soon” posted on his website. ”

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


  20. aiabx

    To me, this is incontrovertible proof that God did not create the universe.
    He bought it at Ikea.

  21. Awesome, maybe pointing this out in geometry class will get me brownie points? :)

    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…

  22. Gary Ansorge

    Don’t forget Earth still generates its own internal heat via a process of fissioning of heavy elements. We don’t know the composition of the core of Jupiter, but I expect it has a number of heavy elements collected way down deep.
    Well, someday we may know for sure,,,

    GAry 7

  23. Steve Dengler

    According to Wikipedia, “the straight sides of the northern polar hexagon are each about 13,800 kilometers long.”

    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…)

  24. Steve Dengler

    Oops! I mean “million” in the last post, not “billion”. The numerical values were right, though.

  25. HenrikOlsen

    Emily’s blog ends with a comment that the experiment isn’t directly applicable, as the polygons in the experiments are caused by interference between the stationary walls and the rotating plate.
    From what I remember, Saturn’s atmosphere rotates at different speeds at different latitudes so there will still be a shear effect, so I think it’s applicable, though probably with some modifications.

  26. Tukla in Iowa

    At least it’s not an inverted pentagram.

  27. andy

    Well it’s obviously a distress signal from the crashed Zetan spacecraft under the south pole of Enceladus (it isn’t tidal forces driving the geysers, its the decay of radioactive elements in the hyperdrive).

  28. The hexagon is pretty neat on it’s own, but if you want a real circus sideshow, you’ve got to hear Hoagland’s downright wacky ranting on the subject. NASA doesn’t know what it is, but Hoagland just jumps out there and says that it’s free energy from another plane. What a kook.

  29. Irene

    Josie Says:
    April 3rd, 2007 at 1:34 pm
    I always think it’s funny when people see something with angles, and assume it has to be ‘unnatural’ in some way. Haven’t these people ever looked at a bee’s hive, or a sunflower?

    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

  30. What a beautiful sight! We will continue to discover amazing things as we continue our exploration of space. I can’t wait.

  31. Funny that Emily found a group doing that fluid theory study. I just heard a different guy (Dr. Georgios Vatistas ) on CBC’s Quirks and Quarks doing the same thing, finding stable geometric shapes in a fluid vortex, and he said he was merely validating the work of Nobel Prize winner J.J. Thomson.

    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.

  32. George

    The article: “Saturn’s north polar hexagon” Mar. 28, 2007, by Emily Lakdawalla, in The Planetary Society Weblog, and the comment by DoctorAtlantis [May 28th, 2008 at 5:10 pm] in Blogs/Bad Astronomy (http://blogs.discovermagazine.com/badastronomy/2007/04/03/a-hex-on-saturn/) require clarifications. Richard Hendricks, a space enthusiast, pointed out in Emily’s article an arXiv paper, published in 2006, titled “Polygons on a Rotating Fluid Surface”, by Thomas Jansson et al. This paper was the precursor of a subsequent article that appeared in Physical Review Letters [Phys. Rev. Lett. 96, 2006, 174502] by the same authors: http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000096000017174502000001&idtype=cvips&gifs=yes. The erratum that accompanies the previously mentioned paper clarifies DoctorAtlantis’s comment.

    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.

  33. Jeff Allen

    Following on the discussion and the question of “walls” to the container.

    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.

  34. john

    no matter what is…. it is natural.


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