Re: Revisit issue of growing things on Mars

From	Larry Moore <larry@wightman.ca>
Newsgroups	rec.arts.sf.written
Subject	Re: Revisit issue of growing things on Mars
Date	2015-10-24 12:56 +0000
Organization	A noiseless patient Spider
Message-ID	<n0fv57$u0e$1@dont-email.me> (permalink)
References	(1 earlier) <a74598c5-4126-4cde-afca-96724b78ac48@googlegroups.com> <d8u3hmF5jpsU1@mid.individual.net> <a57b5bc4-7dc6-4b34-936a-88601244d681@googlegroups.com> <nwoJ8F.DB5@kithrup.com> <8ace6372-1704-4055-b89f-15243a5b9d99@googlegroups.com>

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On 2015-10-23, petertrei@gmail.com <petertrei@gmail.com> wrote:
> On Friday, October 23, 2015 at 11:45:13 AM UTC-4, Dorothy J Heydt wrote:
>> In article <a57b5bc4-7dc6-4b34-936a-88601244d681@googlegroups.com>,
>>  <petertrei@gmail.com> wrote:
>> >On Friday, October 23, 2015 at 2:48:25 AM UTC-4, Robert Bannister wrote:
>> >> On 23/10/2015 8:38 AM, Quadibloc wrote:
>> >> > On Thursday, October 22, 2015 at 6:15:11 PM UTC-6, Dimensional
>> >Traveler wrote:
>> >> >> On 10/21/2015 8:38 PM, Dorothy J Heydt wrote:
>> >> >>> In article <56285170$0$1675$742ec2ed@news.sonic.net>,
>> >> >>> Dimensional Traveler  <dtravel@sonic.net> wrote:
>> >> >
>> >> >>>> Step 1: throw lots of icy comets at planet.
>> >> >
>> >> >>> That's certainly one of the steps.  I'm not sure if it's 1 or
>> >> >>> not.
>> >> >
>> >> >> Is there something else that has to be done on/to the planet before you
>> >> >> can start throwing giant snowballs at it?  Or that would be
>> >> >> significantly easier to do before rather than after?
>> >> >
>> >> > I'm certainly inclined towards doing it rather early in the plan. It's much
>> >> > easier to throw comets at a planet, if one's intentions are benign,
>> >when there
>> >> > isn't anything important for them to accidentally *hit* yet.
>> >> >
>> >> > If the plan included increasing Mars' gravity, say by dropping
>> >Mercury on it,
>> >> > then, as that would (ultimately) reduce the rate at which volatiles
>> >escape into
>> >> > space (and it would also, temporarily, make Mars rather *hot*, given the
>> >> > release of energy involved, resulting in the loss of a lot of volatiles) one
>> >> > would do _that_ before sending in the comets. But that kind of plan involves
>> >> > far-future technology, and thus is not the usual sort of terraforming plan.
>> >> 
>> >> Isn't one of Mars's moons close to losing its orbit or am I totally 
>> >> off-beam? Maybe it would be a good idea to help it on its way first.
>> >
>> >It isn't even near big enough.
>> >
>> >Running the numbers....
>> >
>> >(all weights at Earth gravity)
>> >
>> >Earth's atmosphere weighs 5e18 kg
>> >Mars' surface area is 27.5% of Earth's.
>> >Thus, to put the same atmosphereic mass/surface 
>> >area on Mars, we'd need 1.4e18 kg of gases
>> >
>> >That would provide the same amount of shielding as
>> >we get from Earth's atmosphere.
>> >
>> >But, since we're terraforming, we also need to be
>> >able to breath. Since Mars' gravity is 37.6% of
>> >Earth's, the pressure at the surface would only be
>> >0.376 atmosphere, and unbreathable (equiv to over
>> >24,000 feet, or 7.5 km). To get 1 atm pressure on
>> >Mars' surface, we'd need 3.7e18 kg of gases (or
>> >arrange for a 50% oxygen atmosphere).
>> >
>> >Water isn't air, and an ice asteroid wouldn't create
>> >that much atmosphere, but I'll use water as a proxy to
>> >give an approximate idea of the size of object needed.
>> >
>> >1.4e18  kg of ice = 140 km diameter
>> >3.76e18 kg of ice = 200 km diameter (about the size of Mimas)
>> >
>> >This is well into 'earth/mars-shattering Kaboom!' 
>> >territory. I'd highly advise dropping much smaller
>> >chunks.
>> 
>> If you can really fine-tune your orbits, maybe several
>> Mars-grazing passes to let the Oort-object sublime off a lot of
>> its mass before its final impact?  Note that I am not a
>> physicist, and don't have the foggiest whether this would work or
>> not.  One might have to mount thrusters on the object and nudge
>> it after each pass.
>
> "Several passes"? Think about the size - over 100 miles across,
> and the thinness of the Martian atmosphere. I don't think this
> would work.
>
> pt

Does Roche's Limit also apply here

-- 
Just do the work you find in front of you and enjoy yourself.

Thread

Revisit issue of growing things on Mars "a425couple" <a425couple@hotmail.com> - 2015-10-17 14:44 -0700
  Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-18 00:37 +0000
    Re: Revisit issue of growing things on Mars Robert Carnegie <rja.carnegie@excite.com> - 2015-10-17 22:23 -0700
      Re: Revisit issue of growing things on Mars Gutless Umbrella Carrying Sissy <taustinca@gmail.com> - 2015-10-17 22:47 -0700
        Re: Revisit issue of growing things on Mars Greg Goss <gossg@gossg.org> - 2015-10-18 17:24 -0600
          Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-19 00:51 +0000
            Re: Revisit issue of growing things on Mars "J. Clarke" <j.clarke.873638@gmail.com> - 2015-10-18 21:12 -0400
              Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-19 02:02 +0000
                Re: Revisit issue of growing things on Mars Dimensional Traveler <dtravel@sonic.net> - 2015-10-18 20:02 -0700
                Re: Revisit issue of growing things on Mars "Brian M. Scott" <b.scott@csuohio.edu> - 2015-10-18 23:34 -0400
                Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-19 04:32 +0000
                Re: Revisit issue of growing things on Mars wdstarr@panix.com (William December Starr) - 2015-10-19 11:28 -0400
                Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-19 18:44 +0000
                Re: Revisit issue of growing things on Mars Robert Carnegie <rja.carnegie@excite.com> - 2015-10-20 03:05 -0700
                Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-19 04:31 +0000
                Re: Revisit issue of growing things on Mars Walter Bushell <proto@panix.com> - 2015-10-19 16:50 -0400
                Re: Revisit issue of growing things on Mars "J. Clarke" <j.clarke.873638@gmail.com> - 2015-10-18 23:16 -0400
                Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-19 04:34 +0000
          Re: Revisit issue of growing things on Mars Robert Bannister <robban@clubtelco.com> - 2015-10-19 12:25 +0800
          Re: Revisit issue of growing things on Mars Gutless Umbrella Carrying Sissy <taustinca@gmail.com> - 2015-10-19 01:34 -0700
      Re: Revisit issue of growing things on Mars William Vetter <mdhangton@gmail.com> - 2015-10-19 01:01 -0400
        Re: Revisit issue of growing things on Mars Lawrence Watt-Evans <lwe@sff.net> - 2015-10-19 01:25 -0400
          Re: Revisit issue of growing things on Mars ted@loft.tnolan.com (Ted Nolan <tednolan>) - 2015-10-19 06:00 +0000
            Re: Revisit issue of growing things on Mars Greg Goss <gossg@gossg.org> - 2015-10-19 00:15 -0600
            Re: Revisit issue of growing things on Mars Lawrence Watt-Evans <lwe@sff.net> - 2015-10-19 02:39 -0400
              Re: Revisit issue of growing things on Mars Robert Carnegie <rja.carnegie@excite.com> - 2015-10-19 05:32 -0700
              Re: Revisit issue of growing things on Mars Kevrob <kevrob@my-deja.com> - 2015-10-19 13:21 -0700
        Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-19 13:22 +0000
          Re: Revisit issue of growing things on Mars petertrei@gmail.com - 2015-10-19 08:04 -0700
          Re: Revisit issue of growing things on Mars Quadibloc <jsavard@ecn.ab.ca> - 2015-10-19 17:13 -0700
            Re: Revisit issue of growing things on Mars David Johnston <David@block.net> - 2015-10-19 18:31 -0600
              Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-20 02:17 +0000
                Re: Revisit issue of growing things on Mars David Johnston <David@block.net> - 2015-10-19 20:47 -0600
                Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-20 04:03 +0000
                Re: Revisit issue of growing things on Mars William Vetter <mdhangton@gmail.com> - 2015-10-20 00:33 -0400
                Re: Revisit issue of growing things on Mars "John F. Eldredge" <john@jfeldredge.com> - 2015-10-20 23:23 +0000
                Re: Revisit issue of growing things on Mars Greg Goss <gossg@gossg.org> - 2015-10-20 17:55 -0600
                Re: Revisit issue of growing things on Mars mzenier@eskimo.com (Mark Zenier) - 2015-10-20 17:00 +0000
                Re: Revisit issue of growing things on Mars Dimensional Traveler <dtravel@sonic.net> - 2015-10-20 20:38 -0700
                Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-21 04:06 +0000
                Re: Revisit issue of growing things on Mars "J. Clarke" <j.clarke.873638@gmail.com> - 2015-10-21 04:09 -0400
                Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-21 13:19 +0000
                Re: Revisit issue of growing things on Mars "J. Clarke" <j.clarke.873638@gmail.com> - 2015-10-21 18:17 -0400
                Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-21 23:31 +0000
                Re: Revisit issue of growing things on Mars "J. Clarke" <j.clarke.873638@gmail.com> - 2015-10-21 23:22 -0400
                Re: Revisit issue of growing things on Mars Dimensional Traveler <dtravel@sonic.net> - 2015-10-21 20:01 -0700
                Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-22 03:38 +0000
                Re: Revisit issue of growing things on Mars Dimensional Traveler <dtravel@sonic.net> - 2015-10-22 17:11 -0700
                Re: Revisit issue of growing things on Mars Quadibloc <jsavard@ecn.ab.ca> - 2015-10-22 17:38 -0700
                Re: Revisit issue of growing things on Mars Greg Goss <gossg@gossg.org> - 2015-10-22 22:28 -0600
                Re: Revisit issue of growing things on Mars Walter Bushell <proto@panix.com> - 2015-10-26 23:16 -0400
                Re: Revisit issue of growing things on Mars Robert Bannister <robban@clubtelco.com> - 2015-10-23 14:48 +0800
                Re: Revisit issue of growing things on Mars petertrei@gmail.com - 2015-10-23 08:07 -0700
                Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-23 15:33 +0000
                Re: Revisit issue of growing things on Mars petertrei@gmail.com - 2015-10-23 10:10 -0700
                Re: Revisit issue of growing things on Mars Dimensional Traveler <dtravel@sonic.net> - 2015-10-23 19:07 -0700
                Re: Revisit issue of growing things on Mars Larry Moore <larry@wightman.ca> - 2015-10-24 12:56 +0000
                Re: Revisit issue of growing things on Mars Cryptoengineer <treifamily@gmail.com> - 2015-10-24 10:57 -0500
                Re: Revisit issue of growing things on Mars Anthony Frost <Vulch@vulch.org> - 2015-10-25 10:40 +0100
                Re: Revisit issue of growing things on Mars wdstarr@panix.com (William December Starr) - 2015-10-25 17:23 -0400
                Re: Revisit issue of growing things on Mars Cryptoengineer <treifamily@gmail.com> - 2015-10-25 16:41 -0500
                Re: Revisit issue of growing things on Mars Thomas Koenig <tkoenig@netcologne.de> - 2015-10-25 22:32 +0000
                Re: Revisit issue of growing things on Mars Robert Bannister <robban@clubtelco.com> - 2015-10-26 10:39 +0800
                Re: Revisit issue of growing things on Mars Cryptoengineer <treifamily@gmail.com> - 2015-10-25 21:47 -0500
                Re: Revisit issue of growing things on Mars Robert Bannister <robban@clubtelco.com> - 2015-10-27 10:42 +0800
                Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-23 00:57 +0000
                Re: Revisit issue of growing things on Mars Walter Bushell <proto@panix.com> - 2015-10-26 23:12 -0400
                Re: Revisit issue of growing things on Mars David DeLaney <daviddelaney@earthlink.net> - 2015-10-28 20:33 -0500
              Re: Revisit issue of growing things on Mars William Vetter <mdhangton@gmail.com> - 2015-10-19 23:33 -0400
              Re: Revisit issue of growing things on Mars Robert Bannister <robban@clubtelco.com> - 2015-10-20 15:00 +0800
                Re: Revisit issue of growing things on Mars David Johnston <David@block.net> - 2015-10-20 01:09 -0600
                Re: Revisit issue of growing things on Mars William Vetter <mdhangton@gmail.com> - 2015-10-24 05:17 -0400
                Re: Revisit issue of growing things on Mars Cryptoengineer <treifamily@gmail.com> - 2015-10-24 10:43 -0500
                Re: Revisit issue of growing things on Mars "J. Clarke" <j.clarke.873638@gmail.com> - 2015-10-24 13:27 -0400
                Re: Revisit issue of growing things on Mars William Vetter <mdhangton@gmail.com> - 2015-10-25 10:45 -0400
                Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-24 16:01 +0000
                Re: Revisit issue of growing things on Mars Joy Beeson <jbeeson@invalid.net.invalid> - 2015-10-24 23:16 -0300
                Re: Revisit issue of growing things on Mars Robert Bannister <robban@clubtelco.com> - 2015-10-26 10:41 +0800
                Re: Revisit issue of growing things on Mars Bill Gill <billnews2@cox.net> - 2015-10-25 08:37 -0500
                Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-25 14:10 +0000
                Re: Revisit issue of growing things on Mars David DeLaney <daviddelaney@earthlink.net> - 2015-10-25 09:43 -0500
                Re: Revisit issue of growing things on Mars Cryptoengineer <treifamily@gmail.com> - 2015-10-25 11:19 -0500
                Re: Revisit issue of growing things on Mars Bill Gill <billnews2@cox.net> - 2015-10-25 11:42 -0500
                Re: Revisit issue of growing things on Mars Robert Bannister <robban@clubtelco.com> - 2015-10-26 10:43 +0800
                Re: Revisit issue of growing things on Mars Larry Moore <larry@wightman.ca> - 2015-10-25 18:18 +0000
                Re: Revisit issue of growing things on Mars Greg Goss <gossg@gossg.org> - 2015-10-25 12:54 -0600
                Re: Revisit issue of growing things on Mars William Vetter <mdhangton@gmail.com> - 2015-10-25 12:07 -0400
                Re: Revisit issue of growing things on Mars wdstarr@panix.com (William December Starr) - 2015-10-25 17:32 -0400
                Re: Revisit issue of growing things on Mars William Vetter <mdhangton@gmail.com> - 2015-10-25 19:49 -0400
                Re: Revisit issue of growing things on Mars Robert Bannister <robban@clubtelco.com> - 2015-10-26 10:47 +0800
                Re: Revisit issue of growing things on Mars Greg Goss <gossg@gossg.org> - 2015-10-26 03:52 -0600
                Re: Revisit issue of growing things on Mars Robert Bannister <robban@clubtelco.com> - 2015-10-27 10:44 +0800
        Re: Revisit issue of growing things on Mars Quadibloc <jsavard@ecn.ab.ca> - 2015-10-19 17:10 -0700
          Re: Revisit issue of growing things on Mars "J. Clarke" <j.clarke.873638@gmail.com> - 2015-10-19 22:02 -0400
          Re: Revisit issue of growing things on Mars Thomas Koenig <tkoenig@netcologne.de> - 2015-10-20 05:07 +0000
            Re: Revisit issue of growing things on Mars William Vetter <mdhangton@gmail.com> - 2015-10-20 01:27 -0400
              Re: Revisit issue of growing things on Mars Thomas Koenig <tkoenig@netcologne.de> - 2015-10-20 21:17 +0000
          Re: Revisit issue of growing things on Mars Robert Carnegie <rja.carnegie@excite.com> - 2015-10-20 03:00 -0700
            Re: Revisit issue of growing things on Mars Quadibloc <jsavard@ecn.ab.ca> - 2015-10-20 11:20 -0700
              Re: Revisit issue of growing things on Mars petertrei@gmail.com - 2015-10-20 11:49 -0700
                Re: Revisit issue of growing things on Mars Quadibloc <jsavard@ecn.ab.ca> - 2015-10-21 03:13 -0700
                Re: Revisit issue of growing things on Mars petertrei@gmail.com - 2015-10-21 08:21 -0700
                Re: Revisit issue of growing things on Mars Kevrob <kevrob@my-deja.com> - 2015-10-21 17:29 -0700
                Re: Revisit issue of growing things on Mars Cryptoengineer <treifamily@gmail.com> - 2015-10-21 22:05 -0500
                Re: Revisit issue of growing things on Mars Walter Bushell <proto@panix.com> - 2015-10-26 23:03 -0400
                Re: Revisit issue of growing things on Mars wdstarr@panix.com (William December Starr) - 2015-10-27 08:37 -0400
                Re: Revisit issue of growing things on Mars "Brian M. Scott" <b.scott@csuohio.edu> - 2015-10-27 19:28 -0400
                Re: Revisit issue of growing things on Mars Larry Moore <larry@wightman.ca> - 2015-10-28 20:28 +0000
                Re: Revisit issue of growing things on Mars wdstarr@panix.com (William December Starr) - 2015-10-29 06:07 -0400
                Re: Revisit issue of growing things on Mars Robert Bannister <robban@clubtelco.com> - 2015-10-22 09:03 +0800
                Re: Revisit issue of growing things on Mars Robert Carnegie <rja.carnegie@excite.com> - 2015-10-21 21:17 -0700
                Re: Revisit issue of growing things on Mars wdstarr@panix.com (William December Starr) - 2015-10-25 17:42 -0400
                Re: Revisit issue of growing things on Mars Walter Bushell <proto@panix.com> - 2015-10-26 23:05 -0400
                Re: Revisit issue of growing things on Mars mzenier@eskimo.com (Mark Zenier) - 2015-10-21 15:55 +0000
                Re: Revisit issue of growing things on Mars "nuny@bid.nes" <Alien8752@gmail.com> - 2015-10-22 23:19 -0700
                Re: Revisit issue of growing things on Mars David DeLaney <daviddelaney@earthlink.net> - 2015-10-24 02:16 -0500
                Re: Revisit issue of growing things on Mars Quadibloc <jsavard@ecn.ab.ca> - 2015-10-24 14:33 -0700
          Re: Revisit issue of growing things on Mars Bill Gill <billnews2@cox.net> - 2015-10-21 08:13 -0500
      Re: Revisit issue of growing things on Mars Walter Bushell <proto@panix.com> - 2015-10-19 16:42 -0400
        Re: Revisit issue of growing things on Mars Quadibloc <jsavard@ecn.ab.ca> - 2015-10-19 17:15 -0700
          Re: Revisit issue of growing things on Mars "Brian M. Scott" <b.scott@csuohio.edu> - 2015-10-19 20:46 -0400
          Re: Revisit issue of growing things on Mars djheydt@kithrup.com (Dorothy J Heydt) - 2015-10-20 02:18 +0000
            Re: Revisit issue of growing things on Mars Quadibloc <jsavard@ecn.ab.ca> - 2015-10-20 11:15 -0700
            Re: Revisit issue of growing things on Mars Greg Goss <gossg@gossg.org> - 2015-10-20 18:00 -0600
              Re: Revisit issue of growing things on Mars William Vetter <mdhangton@gmail.com> - 2015-10-20 20:44 -0400
    Re: Revisit issue of growing things on Mars "artyw2@yahoo.com" <artyw2@yahoo.com> - 2015-10-20 14:51 -0700
  Re: Revisit issue of growing things on Mars Des <desmondkavanagh@gmail.com> - 2015-10-22 09:59 -0700

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