Re: Off on a Comet!

Eric Watt Forste (
Thu, 13 Feb 1997 10:24:10 -0800

Dasher asks:
>quoth Arkuat--
>: ... my celestial mechanics is still inadequate to make
>: the task of calculating delta-vees WRT Earth from the raw orbital
>: elements anything but daunting. But I'm working on it. I should just
>: give in and get a copy of Dance of the Planets, I know.
>What's that?

It's a software orrery for MS-DOS.

Greg Burch showed it to me on his laptop a few months ago at Max's
house. I had never seen a rotatable 3D view of the asteroids in
their orbits before, and so it hadn't really sunk in for me that
the Trojan asteroids wander around up to 30 degrees fore and aft
of the relevant libration point, and that works out to several AU.
All the diagrams I had seen before show the Trojans clustered at
Jupiter's L4 and L5 points like tight little bundles (and the Belt
confined to the plane of the ecliptic), but in fact, the Belt is
toroidal like a giant 3D donut and the Trojans are like two *huge*
spherical Mickey Mouse ears stuck on the donut. Probably most of
the people on this list realized this long ago, but it was news to
me and I got a big charge out of it. As I said, I've got a lot of
catching up to do when it comes to celestial mechanics.

Mouseketeer hats will never look the same to me now. Thanks, Greg.

Eric Watt Forste ++ ++