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Re: A Dream: Mercury in a Spacesuit

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In article <XnsA5B11238E663Cmelchizedek@216.166.97.131>,
Cryptoengineer <treifamily@gmail.com> said:

> wdstarr@panix.com (William December Starr) wrote 
> 
>> I Could Be Wrong, but I'm pretty sure that if Body_1 is in a stable
>> orbit around Body_2 then by definition it's possible for Body_3 to
>> find a stable orbit around Body_1 --
>> 
>>    which is a lot easier to parse if I change it to "if PLANET is in
>>    a stable orbit around STAR then by definition it's possible for
>>    SMALLER_THING to find a stable orbit around PLANET.
>> 
>> -- as long as it's feasible to think of all three as point-masses
>> anyway, so you don't have to worry about "Will that third thing
>> _fit_ inbetween the first two?"
>
> Well, no. The Wikipedia "Hill Sphere" article enlightened me on this.
> The "Hill Sphere" is the volume in which a stable orbit can be 
> established around a body. For (for example) the Space Shuttle, this
> is much smaller than the object itself (12 cm or so???? in diameter)

Well I _did_ say that bit about thinking of them all as
point-masses, on account of physics is so much more elegant than
engineering.  But basically, okay, I was wrong.

-- wds

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Thread

A Dream:  Mercury in a Spacesuit Joe Bernstein <joe@sfbooks.com> - 2016-02-16 08:42 -0800
  Re: A Dream:  Mercury in a Spacesuit Greg Goss <gossg@gossg.org> - 2016-02-16 17:20 -0700
    Re: A Dream:  Mercury in a Spacesuit "nuny@bid.nes" <Alien8752@gmail.com> - 2016-02-16 17:39 -0800
      Re: A Dream:  Mercury in a Spacesuit Cryptoengineer <treifamily@gmail.com> - 2016-02-16 23:39 -0600
      Re: A Dream:  Mercury in a Spacesuit David DeLaney <daviddelaney@earthlink.net> - 2016-02-17 03:49 -0600
    Re: A Dream:  Mercury in a Spacesuit "a425couple" <a425couple@hotmail.com> - 2016-02-16 19:34 -0800
    Re: A Dream:  Mercury in a Spacesuit Joe Bernstein <joe@sfbooks.com> - 2016-02-16 20:33 -0800
  Re: A Dream:  Mercury in a Spacesuit Butch Malahide <fred.galvin@gmail.com> - 2016-02-16 18:42 -0800
    Re: A Dream:  Mercury in a Spacesuit Don Kuenz <garbage@crcomp.net> - 2016-02-17 17:36 +0000
  Re: A Dream:  Mercury in a Spacesuit wdstarr@panix.com (William December Starr) - 2016-02-16 22:14 -0500
    Re: A Dream:  Mercury in a Spacesuit hamish.laws@gmail.com - 2016-02-16 19:26 -0800
    Re: A Dream:  Mercury in a Spacesuit Don Bruder <dakidd@sonic.net> - 2016-02-16 19:39 -0800
      Re: A Dream:  Mercury in a Spacesuit Joe Bernstein <joe@sfbooks.com> - 2016-02-16 21:24 -0800
        Re: A Dream:  Mercury in a Spacesuit Joe Bernstein <joe@sfbooks.com> - 2016-02-22 22:41 -0800
    Re: A Dream:  Mercury in a Spacesuit Cryptoengineer <treifamily@gmail.com> - 2016-02-16 23:46 -0600
      Re: A Dream:  Mercury in a Spacesuit wdstarr@panix.com (William December Starr) - 2016-02-18 22:58 -0500
      Re: A Dream:  Mercury in a Spacesuit Quadibloc <jsavard@ecn.ab.ca> - 2016-02-18 20:51 -0800
  Re: A Dream:  Mercury in a Spacesuit "a425couple" <a425couple@hotmail.com> - 2016-02-16 19:56 -0800
  Re: A Dream:  Mercury in a Spacesuit Quadibloc <jsavard@ecn.ab.ca> - 2016-02-17 00:47 -0800
    Re: A Dream:  Mercury in a Spacesuit Greg Goss <gossg@gossg.org> - 2016-02-17 02:13 -0700
      Re: A Dream:  Mercury in a Spacesuit Quadibloc <jsavard@ecn.ab.ca> - 2016-02-17 11:18 -0800
  Re: A Dream:  Mercury in a Spacesuit "a425couple" <a425couple@hotmail.com> - 2016-02-17 13:55 -0800
    Re: A Dream:  Mercury in a Spacesuit Robert Carnegie <rja.carnegie@excite.com> - 2016-02-18 01:58 -0800
      Re: A Dream:  Mercury in a Spacesuit Greg Goss <gossg@gossg.org> - 2016-02-18 09:48 -0700
      Re: A Dream:  Mercury in a Spacesuit wdstarr@panix.com (William December Starr) - 2016-02-18 23:04 -0500
        Re: A Dream:  Mercury in a Spacesuit Robert Carnegie <rja.carnegie@excite.com> - 2016-02-19 02:20 -0800
          Re: A Dream:  Mercury in a Spacesuit Cryptoengineer <treifamily@gmail.com> - 2016-02-19 23:30 -0600
  Re: A Dream:  Mercury in a Spacesuit peterwezeman@hotmail.com - 2016-03-14 18:38 -0700
    Re: A Dream:  Mercury in a Spacesuit Greg Goss <gossg@gossg.org> - 2016-03-14 20:28 -0600
    Re: A Dream:  Mercury in a Spacesuit wdstarr@panix.com (William December Starr) - 2016-03-18 11:45 -0400
      Re: A Dream:  Mercury in a Spacesuit ted@loft.tnolan.com (Ted Nolan <tednolan>) - 2016-03-18 16:13 +0000
      Re: A Dream:  Mercury in a Spacesuit Robert Carnegie <rja.carnegie@excite.com> - 2016-03-18 09:48 -0700
        Re: A Dream:  Mercury in a Spacesuit Peter Trei <petertrei@gmail.com> - 2016-03-18 09:57 -0700
      Re: A Dream:  Mercury in a Spacesuit Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> - 2016-03-18 19:48 +0100
        Re: A Dream:  Mercury in a Spacesuit Kevrob <kevrob@my-deja.com> - 2016-03-18 12:10 -0700
      Re: A Dream:  Mercury in a Spacesuit Steve Coltrin <spcoltri@omcl.org> - 2016-03-21 19:20 -0600
        Re: A Dream:  Mercury in a Spacesuit David DeLaney <daviddelaney@earthlink.net> - 2016-03-22 15:16 -0500
          Re: A Dream:  Mercury in a Spacesuit Robert Carnegie <rja.carnegie@excite.com> - 2016-03-22 14:12 -0700
          Re: A Dream:  Mercury in a Spacesuit Steve Coltrin <spcoltri@omcl.org> - 2016-03-24 10:48 -0600

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