The cool thing about this video for me was the visualization of these equi-energy "tubes" that allow transfer of bodies to a large number of places in the solar system consistent with that amount of energy. For planetary travel, these "tubes" are the space equivalent of _rivers_ and _sea lanes_/_trade winds_ that enabled millennia of early commerce on the Earth's surface. Just as the West Coast is receiving debris from Japan many, many months after the tsunami, the Earth is receiving debris from Mars, many, many years after some collision with Mars kicked this debris up into space. I would imagine that analogous "space tubes" connect our Sun with nearby stars in our galaxy. These tubes would provide a mechanism for transporting some small amounts of material over the billions of years of the Solar System's existence. I presume that every planetary system has ejected 1 or more significant sized planet that is free to travel these tubes and cause havoc in some other planetary system millions of years later. At 07:15 PM 1/23/2013, Fred lunnon wrote:

I watched this from start to finish in one sitting --- unput-downable!

He just slipped this in briefly towards the end, but it seemed potentially significant to me: in a dust cloud, dissipation causes (non-escaping) particles to congregate in stable "torus" islands. If I've undertood this correctly, it implies that once a system of two massive bodies has been established, then the formation of a (coarsely) determined planetary system is guaranteed within a relatively small timescale.

Or maybe this is already well-known, and I just hadn't caught up ...

Fred Lunnon

On 1/23/13, Henry Baker <hbaker1@pipeline.com> wrote:

...

FYI -- Talks about zero/low energy orbit transfers, potential Earth-colliding asteroids, ability of Mars ejecta to reach Earth, etc.

The Interplanetary Transport Network: Mapping Chaotic Motion Through the Solar System, November 2008. Zurich Physics Colloquium.

Shane Ross

55 minutes, 144MB download

http://www2.esm.vt.edu/~sdross/movies/ross-zurich-2008.mov

Free book on this topic:

Dynamical Systems, the Three-Body Problem and Space Mission Design

W.S. Koon, M.W. Lo, J.E. Marsden and S.D. Ross

Free online Copy

312 pages, with 128 illustrations; 16MB download

http://www2.esm.vt.edu/~sdross/books/KoLoMaRo_DMissionBk.pdf

Shane Ross web page:

http://www.shaneross.com/