Difference between revisions of "User:Tohline/Appendix/Ramblings/Saturn"

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=Saturn=
=Saturn=
Here we draw heavily from the review by [https://ui.adsabs.harvard.edu/abs/2019Sci...364.1046S/abstract L. Spilker (14 June 2019)] titled, ''Cassini-Huygens' exploration of the Saturn system:  13 years of discovery'' that has appeared in Science, Vol. 364, Issue 6445, pp. 1046 - 1051.  This review reminds us to emphasize that, although virtually all of the chapters of our [[User:Tohline/H_BookTiledMenu#Tiled_Menu|H_Book]] have been written from the standpoint of analyzing the structure, stability, and dynamics of ''stars'', much of our discussion is applicable in a fairly straightforward manner to studies of ''planets'' — especially the gas giants — because they are also self-gravitating fluids.


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==Structure and Stability==
Excerpt from the first paragraph on p. 1050 of  [https://ui.adsabs.harvard.edu/abs/2019Sci...364.1046S/abstract L. Spilker (2019)]:
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Saturn's ring system acts like a seismograph, providing a measure of Saturn's internal oscillations (or normal modes) that directly probe the interior of the planet &hellip; and provide a means for measuring its deep rotation rate.  These vibrations, determined by Saturn's nonuniform internal structure, are probably driven by convection inside the planet, which cause oscillations in Saturn's gravity field &hellip; Preliminary modeling of the propagation behavior of this collection of waves provides an interior rotation rate for Saturn of &sim; 10.6 hours &hellip;
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==Hexagon Storm==
==Hexagon Storm==

Revision as of 20:33, 13 July 2019


Saturn

Here we draw heavily from the review by L. Spilker (14 June 2019) titled, Cassini-Huygens' exploration of the Saturn system: 13 years of discovery that has appeared in Science, Vol. 364, Issue 6445, pp. 1046 - 1051. This review reminds us to emphasize that, although virtually all of the chapters of our H_Book have been written from the standpoint of analyzing the structure, stability, and dynamics of stars, much of our discussion is applicable in a fairly straightforward manner to studies of planets — especially the gas giants — because they are also self-gravitating fluids.

Whitworth's (1981) Isothermal Free-Energy Surface
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Structure and Stability

Excerpt from the first paragraph on p. 1050 of L. Spilker (2019):

Saturn's ring system acts like a seismograph, providing a measure of Saturn's internal oscillations (or normal modes) that directly probe the interior of the planet … and provide a means for measuring its deep rotation rate. These vibrations, determined by Saturn's nonuniform internal structure, are probably driven by convection inside the planet, which cause oscillations in Saturn's gravity field … Preliminary modeling of the propagation behavior of this collection of waves provides an interior rotation rate for Saturn of ∼ 10.6 hours …

Hexagon Storm

Image on the Right: obtained from this NASA/JPL site; image on the Left: obtained from this NASA Newsletter. See also the wikipedia page titled, Saturn's hexagon.

FIGURE 1 FIGURE 2

Casini image

Image of Saturn's Hexagon Storm

Post Cassini

Binary Mass-Transfer

Several key references:


FIGURE 3:   Nonlinear-Amplitude Distortions that Develop in Three Separate Model Evolutions
Evolution A Evolution B Evolution C

MFTD (2007)
Model Q0.4D
Animation: video4.mpg
(link is in caption of their Figure 3)

MFSCFEDT (2017)
Model Q0.4P_S1
Animation: apjsaa5bdef26_video.mpg
(link is in caption of their Figure 26)

MFSCFEDT (2017)
Model Q0.5P_G1
Animation: apjsaa5bdef21_video.mpg
(link is in caption of their Figure 21)

Q04DcroppedD.png Q0.4P S1croppedD.png Q0.5P G1croppedD.png
Q04D squareD.png Q0.4P S1 squareD.png Q0.5P G1 squareD.png
Q04D triangleD.png Q0.4P S1 triangleD.png Q0.5P G1 triangleD.png
The evolution identified here as Model Q0.5P_G1 was first discussed in §5.2 of DMTF (2006), wherein it was identified as Model Q0.5-Da; the caption to Figure 7 of that paper contains a link to an (mpeg_file = video3-2.mpg) animation that presents a 3D rendering of this model's evolution.


The following discussion has largely been extracted from §3.1.4 of MFSCFEDT (2017):

In §4 of their paper, MFTD (2007) point out that in the vicinity of the accretor some of the models developed nonlinear-amplitude "equatorial distortions with [azimuthal mode numbers] <math>~6 \ge m \ge 3</math>." As is illustrated by the trio of images displayed in the bottom row of Figure 3, above, at a certain point (or points) in each of these binary mass-transfer evolutions … the disk surrounding the accretor has a triangular shape … This trio of triangular shaped images come from, respectively, evolutionary times: (A, B, C) = (15.3, 17.50, 24.33), as measured in terms of initial orbital periods.

Related Discussions

Whitworth's (1981) Isothermal Free-Energy Surface

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