Here is a report on the JunoCam images at PJ20. Juno did not pass near famous features, but got excellent views of all latitudes. Highlights include:
--More examples of chaotic cyclonic regions (FFRs) that may be generating new spots from their western ends, including cyclones and anticyclones and amorphous dark grey patches, in several northern domains and in the S3 domain.
--First view of the darkened region of N. Temperate Zone (N. Temperate Disturbance) which appears to be partly made up of such dark grey material.
--Specatacular panoramas of the ochre-shaded Equatorial Zone, with a major NEBs dark formation (‘hot spot’) and its large dark bluish festoon; on the small scale, a fascinating variety of clouds and streaks and waves, including previously unobserved phenomena.
--A fine view of the ‘String of Pearls’ in the S2 domain , and of the white cyclonic oblong between two of them, which closely resembles the former STB Ghost.
The report is posted as a PDF, and the full-size figures will be added in a ZIP file. This report covers the non-polar latitudes: Part II, giving an update on the polar regions, wil be added in due course.
- Report-on-PJ20_PartI-w-minifigs.pdf [1.61 MB]
The PJ20 images showing areas near the equator are especially interesting.
Here is an enhanced map-projected image processed from PJ20_34 showing the area from planetographic latitude 5 degrees south to 6.6 degrees north. The image has been processed to better reveal various subtle features and color variations. The enhancement/processing parameters differ for different parts of the image. The enhancement is strongest in areas that have low contrast in the original imaging data.
Various interesting cloud features can be seen; perhaps the strangest one is the 'fleet of ships' (a term first used by John Rogers in his PJ20 report) in the lower right quadrant of the image. Interestingly the 'ships' are oriented at an angle of roughly 30-60 degrees relative to faint north-south oriented striations in this area. The visual impression I get from the image is that the 'ships' are higher in the atmosphere but this could easily be wrong. Similar features are visible in a few Voyager 1 images obtained shortly before closest approach but the new JunoCam images are much better.
A number of additional interesting features are also visible in this image; many of them look very subtle in a true color/contrast version of this image.
Here are the full-size figures for Part II in a ZIP file.
Here are the full-size figures for Part I in a ZIP file.
Here is Part II of the report, covering the polar regions.
These reports on the polar regions are sequential updates which don't contain much background explanation, but overviews of the topics are given at these links:
'Jupiter's polar polygons': https://www.britastro.org/node/12654
'Jupiter's high-latitude hazes' https://www.britastro.org/node/16790