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A naive question. When we look at Jupiter, we see that its features didn't change largely over many years, for instance, the red-spot. If it is composed of gases and liquids, then why aren't the effects of mixing of these fluids visible?

My intuition is that due to very low temperatures ($-145\, ^{\circ}$C), diffusion of fluids doesn't occur and therefore the superficial appearence of Jupiter remains the same.

Py-ser
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kaka
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4 Answers4

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Believe it or not, Jupiter isn't too consistent. Take a look at these pictures, the first taken in 2009 and the second taken in 2010:

enter image description here

and

enter image description here

Quite the difference, eh? Why?

Jupiter's atmosphere is made of zones and belts. Zones are colder and are composed of rising gases; they are dark-colored. Belts are warmer and are composed of falling gases; they are light-colored. The reason the two don't intermix is because of constant flows of wind, similar to the Jetstream. These winds make it hard for bands to mix.

There are two types of explanations for the jets. Shallow models say that the jets are caused by local disturbances. Deep models say that they are the byproduct of rotating cylinders comprising the mantle. At the moment, we don't know which explanation is correct.

Community
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HDE 226868
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    How do you know that both pictures are of the same side of Jupiter? It rotates rather quickly. – Nate Eldredge Oct 29 '14 at 19:05
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    @NateEldredge Well they're rotated similarly enough to not include the great red spot at least. – zibadawa timmy Oct 29 '14 at 19:24
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    Voyager 1 made a timelapse of the surface. For example: https://www.youtube.com/watch?v=rHwkdcppsuo – Sanchises Oct 29 '14 at 19:37
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    Here's a video of the same side of Jupiter, as Voyager approaches. They do some processing to make the image the same size, and some tweening, so it's not "pure", but it makes it obvious that the details do not remain static. https://www.youtube.com/watch?v=l-9ULWGHFD0 – Beska Oct 29 '14 at 19:37
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    @NateEldredge Jupiter, like the sun and the other gas planets, undergoes differential rotation; for two photos separated by many days, Jupiter doesn't have well-defined "sides" like rocky planets do. – rob Oct 29 '14 at 20:39
  • @NateEldredge Note also the white spots near the bottom, which are roughly consistent in both images. True, they could have rotated around, but that would suggest that the other layers should have, too. – HDE 226868 Oct 29 '14 at 22:45
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we see that its features didn't change largely over many years

Jupiter is huge. It is 11 earths across, and 1300 times our volume. The clouds/bands we can see are vastly larger than Earth's entire ecosystem and that means they have a lot more inertia.

Also consider our observation timespan. We have been watching Jupiter* for under 2 centuries, watching it in detail for under 60 years, and watching it in the above picture's detail for under 30 years. Given the scale of Jupiter's weather this is a very short timespan and we should not expect to see major upheavals within one human lifespan. Picture a nice summer day in California, from an insect's perspective - it won't change much in 72 hours, and that's a long time for many bugs.

  • Galileo saw a spot of light. Cassini (the person, not the probe) didn't see all that much detail.
user985366
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paul
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    "Galileo saw a spot of light". Best understatement of a great discovery ever. Good points all around. – HDE 226868 Oct 29 '14 at 14:54
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    Great discoveries often have unassuming appearances. That's what makes them great discoveries. – paul Oct 30 '14 at 11:10
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    @HDE226868 galileo saw 4 spots of light around that one big one, and thats why we call io europa ganymede and callisto the galilean moons of jupiter. – usethedeathstar Nov 05 '14 at 05:48
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Jupiter is highly dynamic:

Jupiter Animated Video Gallery (be sure to look at storm merger video)

Differences Spotted in Jupiter's Big Red Storms

Jupiter's New Red Spot

Jupiter Loses Big Belt; Great Spot Left Hanging

The persistence of Jupiter's Red spot is in fact a bit of a mystery.

Wayfaring Stranger
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Jupiter's features change constantly, thanks to new leaps in the field of Astronomy, i.e Hubble, Spitzer and soon to come in 2018 the James Web telescope, we have been able to see our Universe in ways never imagined. July 1994, when more than 20 pieces of Comet P/Shoemaker-Levy 9 (SL9) plunged into Jupiter's atmosphere it caused a flash of energy bright enough to be seen 400 million miles away. A shock wave generated by ram pressure as the meteor speeds into the planet's atmosphere heats the impacting body to a very high temperature, and as the hot object streaks through the atmosphere, it leaves behind a glowing trail of superheated atmospheric gases and vaporized meteor material, leaving dark smudges behind that rapidly cools and fades in just a few seconds.Therefore changing its atmosphere if only briefly. For more info on Jupiter visit http://ccs.infospace.com/

jenni selman
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  • Jupiter of all the planents DOES CHANGE! It may not appear to be such, but the small changes are there, most seen to be suddle – jenni selman Nov 04 '14 at 22:01