Monday, August 2, 2010

Update on F ring

So after watching the F ring simulation I described earlier go for the weekend, I made some changed and updates. While this forced me to stop the simulation and lose what I had done over the weekend, one of the changes was to use a longer time step because this is a sparse simulation with gravity. The result is that now it is doing an orbit in under 8 hours instead of 36. That factor of 4.5 is huge considering it was looking like this would require 2 years to get anything significant done. Now it should have nice results in 6 months and be in a very good spot by next summer when I will have the time to really go look at what is happening.

The early stuff is fascinating. In particular, I gave the moons inclination, something I had never done before, and they are giving it to the ring. Because gravity is a 1/r^2 force, proximity matters more than elevation. So the ring gets its maximum inclination near the point of closest approach and not when the moon is at maximum elevation.

One of the big questions is how the inclination will impact negative diffusion. It is possible that it could lead to more vertical displacement and less migration of semimajor axis. Only by going through the simulations will I know for certain. I expect that I will have some results to put on my main web site before classes start. Of course, when I do I will put a post here telling all about it.