"Alasdair" . uk wrote in news:cjgn48
:




"AA Institute" wrote in message
om...
Before anybody gives me that look...this question is totally in the
context of a "what if" kind of hypothetical scenario.

Suppose an asteroid somehow, through some super, far future
engineering achievement has been captured into orbit around the Earth.
Now suppose we want to carve it out by detonating a series of missiles
that incrementally hollow their way into the body of such an asteroid.
The material excavated out of the body would create a thin ring system
around the Earth, as I try to illustrate he-

http://uk.geocities.com/aa_spaceagen...arth-ring.html

My main concern with such a project is one of SAFETY. I'd like to know
what a *safe* perigee (minimum) altitude would be necessary to prevent
orbital decay of ring material. I don't want any material from my
hypothetical ring system coming down toward the Earth under any
circumstances. Would the ring material be contained in a narrow plane
of fixed orbital incline, or would it scatter over time? What about
interactivity with particles trapped in the Van Allen radiation belts?
Is there any learnings from the Voyager studies (and now Cassini
studies) of Saturnian rings that could be used to predict the long
term stability of such a *hypothetical* ring system around the Earth
in the future?

Abdul Ahad

I think the moon would prevent the ring from forming properly
Alasdair

There is currently a ring around earth. If you ever look at a 3-D type
map of satelites, (like J-Track 3D
http://science.nasa.gov/RealTime/JTr.../JTrack3D.html)
you'll see that the satellites in geostationary orbit make a nice ring
around earth :-)

There's a couple gotchas to this statement...first J-Track blows up the
relative size of the dot of light relative to the earth to many, many,
many times the actual size of the spacecraft, so it appears more
populated than it is (true...real rings aren't solid, but this is pushing
it). I heard once jupiter had a very small ring that we only discovered
when we sent probes in close to it...anyone know more info about this?

Also, all these man made satellites have position keeping thrusters, to
compensate for things like the moon. I have no idea as to what would
happen to this "ring" if they suddenly just turned them all off, but I
don't think anything major would happen very fast.