Asri-unix.721
net.space
utcsrgv!utzoo!decvax!ucbvax!ARPAVAX:C70:sri-unix!REM@MIT-MC
Mon Feb  8 00:38:38 1982
Horseshoe Orbits
The two satellites are in almost identically the same orbit, thus the
one in the lower/faster/smaller orbit very very slowly overtakes the
other over a period of many orbits. If they were of zero mass, they'd
simply bump into each other as they pass, and be diflected in some
semi-random direction like particles in a sub-atomic accellerator.
But they have enough mass that as they get close to each other they
pull on each other slightly. The one ahead in orbit (the higher/slower
one) is pulled backward, causing it to lose energy and spiral down to
a lower orbit. The one behind in orbit (the lower/faster one) is
pulled forward, causing it to gain energy and spiral up to a higher
orbit. Eventually they are in exactly the same orbit, one behind the
other, and they don't get any closer because the one behind is no
longer traveling faster than the one ahead. But they are still close
together, in fact they are at their closest point now, and they continue
to attract each other. The one ahead continues to lose energy and spiral
into a lower and lower orbit, and the one behind continues to gain energy
and spiral into a higher and higher orbit. The one ahead, being now in
a lower orbit, races ahead, and the behind, being now in a highe orbit,
lags behind. They thus slowly drift apart, the one in front in a lower
oribit and the one behind in a higher orbit, until they are far enough
away to no longer effect each other significantly.

Many many orbits later, their difference in orbits has caused the one
ahead&faster to get nearly a whole orbit ahead of the one behind, and
they start to effect each other but with roles reversed (the one that
was slightly ahead is now almost a full orbit ahead, thus is slightly
behind, and is in the lower/faster orbit on approach; the one that was
slightly behind is now almost a full orbit behind, thus slightly ahead,
and is in the higher/slower orbit on approach).

(I hope this explanation satisfies everybody.)

-----------------------------------------------------------------
gopher://quux.org/ conversion by John Goerzen <[email protected]>
of http://communication.ucsd.edu/A-News/


This Usenet Oldnews Archive
article may be copied and distributed freely, provided:

1. There is no money collected for the text(s) of the articles.

2. The following notice remains appended to each copy:

The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996
Bruce Jones, Henry Spencer, David Wiseman.