Juno has completed its second flyby of Jupiter, skimming close to the atmosphere and managing to get some interesting pictures of Jupiter’s polar regions.
Apparently we’ve never gotten a good look at Jupiter’s poles before. I imagine there’s a lot of frantic technical analysis going on right now at NASA, but not a whole lot of info has been released to the public so far.
We do have a press release, which I’m taking as a small preview of the real science that’s still to come. From the press release, we’ve learned that:
- There’s a heck of a lot of storms, sort of clustered together. It’ll be interesting to find out which way they rotate. Are we looking at cyclones or anticyclones? (The Great Red Spot is an anticyclone, by the way).
- Apparently cast-shadows are visible, suggesting clouds of varying altitudes. I’m guessing we’ll learn something about regional temperature and pressure variations from that.
- The clouds have a bluish tint. In my inexpert opinion, that might indicate elevated concentrations of methane (the gas that makes Uranus and Neptune look so blue). That would be a change from the ammonia clouds we’re used to seeing in Jupiter’s upper atmosphere.
In short, it sounds like Jupiter’s polar regions have a whole separate ecosystem of clouds and storms. Do these storm systems function independently from the belts and zones observed at other longitudes, or could there be some complex relationship at work?
The Juno spacecraft has a little less than two years to find out. Good luck, Juno. We’re all counting on you.
Planet Pailly 
On the bluish tint, are you thinking that the high concentrations might scatter light more (similar to Earth’s atmosphere) or that the methane is bound to something with a bluish color? Just curious.
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I’m just throwing out my best guess based on what it said in the press release. With gas giants, blue usually means methane. Methane tends to absorb red light and reflect blue light back into space.
But a Rayleigh scattering effect (like in Earth’s atmosphere) would make sense to me too, if that’s what the Juno team’s analysis concludes.
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Those first things coming back from Juno so far have been amazing. Those poles! It makes me think back to last year when the stuff from New Horizons first started coming in. At first we didn’t know what we were looking at, and then, slowly, it changed and we’re starting to piece things together. My first thought when I saw the blue was methane, too, but maybe it’s, like you say, scattering. Either way, it’s amazing stuff. A terrific post, too.
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I’m glad I’m not the only one who jumped to that conclusion about methane. I didn’t really get to follow New Horizons as closely I wanted to last year. I was too tied up in my own projects. I’m hoping to make up for that with Juno.
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I’ll bet the pictures are pretty with all the storms.
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They are. It almost looks like marble, with all those storms swirling together. http://www.nasa.gov/sites/default/files/thumbnails/image/pia21030_main_2_north_polar_full-disk_a.png
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Considering how large Jupiter is compared with Earth, it has plenty of room for all sorts of unusual features.
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True enough. We’ll have to wait and see what other surprises Juno can find.
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