This page links to movies of simulations of moonlets embedded in Saturn's rings, particularly the A ring. Significant work has been done on simulating embedded moonlets by Frank Spahn and his collaborators. This work adds to that by adding full particle self-gravity to the smulations. Spahn's group has typically included a forcing toward the midplane to mimic some of the impact of particle self-gravity, but that doesn't produce the clumping effects of gravity wakes (Toomre instabilities). This work also investigates the impact of having broad size distributions of particles on the formation of so called "propellers" adjacent to the moonlets.
| Sim Name | N | Moonlet Size (m) | Particle Diameter (m) | Optical Depth | Particle Density (g/cm^3) | Surface Density (g/cm^2) | Partice Animation | Orbit Properties Animation |
|---|---|---|---|---|---|---|---|---|
| L1 | 795,713 | 260 | 10.4 | 0.1 | 0.5 | 36.1 | grav/no grav | grav/no grav |
| L2 | 127,312 | 260 | 26 | 0.1 | 0.5 | 88.5 | grav/no grav | grav/no grav |
| L3 | 353,652 | 260 | 15.6 | 0.1 | 0.5 | 53.4 | grav/no grav | grav/no grav |
| L4 | 353,659 | 232 | 15.6 | 0.1 | 0.7 | 74.7 | grav | grav |
| L5 | 353,661 | 214 | 15.6 | 0.1 | 0.9 | 96.1 | grav | grav |
| S1 | 759,713 | 26 | 1.04 | 0.1 | 0.7 | 4.97 | grav/no grav | grav/no grav |
| S2 | 127,312 | 26 | 2.6 | 0.1 | 0.7 | 12.3 | grav/no grav | grav/no grav |
| S3 | 254,624 | 26 | 2.6 | 0.2 | 0.7 | 24.6 | grav/no grav | grav/no grav |
| D1 | 389,987 | 26 | q=2.8, 0.52-13 | 0.1 | 0.7 | 21.1 | grav/no grav | grav/no grav |
| D2 | 781,820 | 26 | q=2.8, 0.52-13 | 0.2 | 0.7 | 42.2 | grav/no grav | grav/no grav |
| D3 | 487,535 | 26 | q=2.8, 0.52-3.9 | 0.1 | 0.7 | 14.1 | grav/no grav | grav/no grav |
| D4 | 974,886 | 26 | q=2.8, 0.52-3.9 | 0.2 | 0.7 | 28.6 | grav/no grav | grav/no grav |
| D5 | 1,445,059 | 26 | q=2.8, 0.26-3.9 | 0.2 | 0.7 | grav/no grav | grav/no grav |
This animation shows what simulation D4 without self-gravity might look like at low resolution in a backlit situation. The colors are given simply by the geometric optical depth of the particles in each of the bins. Also shown in a weighted average of the particle sizes in each bin. White would correspond to an average radius of 0 while black is an average diameter of 2 meters or larger. While the particle sizes are noisy, it should be noted that the lobes of the propeller consistently have smaller particles than the other parts of the simulation cell. The average particle size is calculated with each particle weighted by its cross-sectional area. Without this weighting, the shear number of smaller particles in every cell swamps the smaller number of larger particles.
Original paper figures with larger scale
Figure 1 - From ciclops.org
Figure 4- png, gzipped PS
Figure 5- png, gzipped PS
Figure 6- png, gzipped PS
Figure 7- png, gzipped PS
Figure 8- png, gzipped PS
Figure 9- png, gzipped PS
Figure 10- png, gzipped PS
Figure 11- png, gzipped PS
Figure 12- png, gzipped PS
Figure 13- png
Figure 14 - png
Figure 15 - png
