Juno, perijove 11, February 07, 2018 Options

[Gerald]

Part of the perijove-11 data have already been downlinked. So, we should start an according topic.
Here a thumbnail simulation I've rendered a few days ago, in order to see, how Jupiter may appear in JunoCam images:



The simulation is based on SPICE kernels as they have been available last week. Simulated shading is of Lambertian type by solar incidence.

The short appearance of a small portion of a mirror image of Jupiter in the upper and lower left corner indicates an apparent vertical extension of Jupiter of more than 180 degrees in cylindrical coordinates, which is strange. I wonder, whether that's a glitch in my calculations, or whether it can be explained by Juno's curved trajectory close to Jupiter, while JunoCam is taking the simulated image over about 15 seconds.
I don't mean the mirror image (which doesn't appear in real images), but the extension of more than 180 vertical cylindrical degrees.

[Gerald]

Regarding the quantum physical question: When I don't look to the moon, but I see my shadow on the floor, I know, that the moon is there, and forced its wave function to collapse/decohere in my branch of the wave function of the universe.
Regarding Jupiter's chromophores: If the question of the photochemistry of chromophores in Jupiter's atmosphere has a convincing chance to be solved by a sequence of JunoCam images, we can ask for an according campaign, if that's even necessary, since we already have image sequences of the same target area, and the chromophores may need to make their (quantum-physical analog of a) decision, how stable they are.

My expectation is, that they are considerably longer-lived than one Jupiter day. With a global statistical analysis, we'll get mostly shading and scattering effects. Those might be able to be used to make conclusions about the grain size distribution of aerosols in Jupiter's upper atmosphere. We won't distinguish easily effects by polarization. Modeling and subtracting these ingredients might eventually add some constraint to the chemical stability of the chromophores. But if chromophores would change rapidly under sunlight, I'd expect this to be pretty obvious by a systematic change of Jupiter's color as a function of solar illumination, or of distance from the terminator.

I'd think, that long-term changes can be evidenced a little better by considering the bluish hue over Jupiter's polar regions compared to lower latitudes. But even here, we need to consider the overall structure of Jupiter's atmosphere depending on latitude that might act as a latitude-dependend color filter. So, it's certainly a long way to conclusions about microscopical dynamics and photochemistry, at least on the mere basis of JunoCam images.

I'll try to contribute my part to pin these things down as far as the data allow.

[JRehling]

The Moon question is a bit of a facetious one, but one already in the QM community. ("Is the Moon There When Nobody Looks?" is the title of a very intriguing, but very off-topic paper by David Mermin.) Seeing one's shadow violates the spirit of the premise, which is, does physical reality exist when unobserved in any way?

That could take us far off topic, but the relation to Jupiter's chromophores is: If they form rather quickly upon exposure of some fresh, upwelling white clouds to certain conditions of sunlight, it may be pernicious-bounding-on-impossible to witness the process taking place, because the daylight that permits the process alters the conditions.

Even there, I'm being a bit over-wary. We have no idea if the chromophores form on such a rapid timeframe. If they form over a span of hours or days, there's no inherent difficulty. If they form via a process that begins and completes on the scale of seconds or minutes, we do have a problem. But that's just a conjecture to point out the potential difficulty. But in no case do I expect quantum mechanical superpositional states to be a relevant phenomenon.

I certainly agree that the chromophores last longer than a day. We don't (generally) see any profound color differences between parcels of cloud between the morning and evening circumstances. It may be that the chromophores are relatively permanent once created, in which case the only part of the process that we will get to observe will be the creation.

There are certainly many thorny variables: Vertical transport, temperature, solar (UV) illumination, altitude, and then the entire chemistry book. I don't know how close we are to understanding the phenomenon, but these Juno photos certainly seem to offer a new kind of observation in support of understanding it.