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]

The PNG versions of the above images are online on missionjuno, since several hours now. Here another copy, together with the applied masks.
And here the drafts with gamma=0.5, and without trajectory nor shape data, if you like to get close to whatever "natural colors" might mean for electronic displays.

Here a 50% reduced JPG, where you can see structure within the bright cloud, again enhanced to the 4th power of approximately illumination-adjusted radiometric data:


The twice supersampled PNG version is submitted to the missionjuno site.

[JRehling]

There's so much to like here. Great work, once again!

I am struck by the color in that bright cloud: Specifically, the nonuniformity of it. And, again on the note that this non-science instrument may yield some impressive science, I wonder of the utility of this image, and others like it, for providing insight as to the still-unknown chromophores in Jupiter's clouds. If the chemical reactions that produce chromophores are produced at different combinations of altitude and solar incidence, images showing variations in hue in cloud surfaces that have freshly risen could potentially rule out some candidate reactions/compounds.

There is certainly variation in hue over that bright cloud. How much is due to compositional variation and how much due to variations in illumination is another question. I'm sure it wouldn't be trivial to perform the required analysis, but this is one of the first images I've seen that suggests that it's possible.

[Gerald]

There's so much to like here. Great work, once again!

I am struck by the color in that bright cloud: Specifically, the nonuniformity of it. And, again on the note that this non-science instrument may yield some impressive science, I wonder of the utility of this image, and others like it, for providing insight as to the still-unknown chromophores in Jupiter's clouds. If the chemical reactions that produce chromophores are produced at different combinations of altitude and solar incidence, images showing variations in hue in cloud surfaces that have freshly risen could potentially rule out some candidate reactions/compounds.

There is certainly variation in hue over that bright cloud. How much is due to compositional variation and how much due to variations in illumination is another question. I'm sure it wouldn't be trivial to perform the required analysis, but this is one of the first images I've seen that suggests that it's possible.

This, and other questions are going to be discussed on a new tab on the missionjuno site, called "Think Tank".
The last inconsitencies I've been aware of have been fixed early today, such that I think, that I can point to this new feature now.
Candy's basic idea is an experiment with "science in a fishbowl", as far as it's possible with topics that are eventually intended to be published in regular peer-reviewed papers.

Within the PJ11 thread, I've posted links to a first set of PJ11 maps. They will e.g. help to narrow down the locations in terms of longitude and planetocentric latitude, which areas will be worth to render in high resolution, in order to measure small-scale features, like the bright cloud and its structure.
Regarding the color, it's always better to have at least two images of the same target to mostly rule out camera and processing artifacts.

[JRehling]

This, and other questions are going to be discussed on a new tab on the missionjuno site, called "Think Tank".

That's great to know, Gerald. I'll enjoy seeing it.

With the chromophores question, there's a bit of a real world case here of "How do you know the refrigerator light goes off when you shut the door?" Or, the somewhat more mystical quantum mechanical question (yes, facetious) "Is the Moon still there when I don't look at it?" If sunlight plays a role in the creation of chromophores, and nobody doubts that it does, getting multiple observations, or even a single observation, is troubled a bit by the expectation that the phenomenon in question will vary over any set of observations. If the chromophores evolve (chemically or physically or via transport) much faster than a single Juno orbit, then we may have to rely upon a single hours-long perijove to study this phenomenon. Or, of course, several perijoves, studying the phenomenon longitudinally. (For example, you don't need to visit a city for 80 years to understand how people of all ages dress. You can see children, teenagers, young adults, older adults in one hour and piece together the timeline from those many cases.)

So, it may be informative to image the same active cloud formation twice in a perijove, but here I think the secondary role of imaging runs afoul of the mission's top priority, which wouldn't allow that sort of wasteful repointing.

In any event, good job and thank you for reducing the raw data to the point where such questions can even be asked!