Is there a perfect amount of lunar atmosphere?

[mithridates]

<p>Assuming that we won't be installing a full atmosphere on the moon since it would be gone in a few thousand years and would remove some of the aspects that make the moon attractice (mass drivers, astronomy, etc.), wouldn't it be in our best interest to have a very thin atmosphere?</p><p>A very thin atmosphere would have the following benefits:</p><p>1) It would destroy micrometeorites, those of a few mm or cm in diameter that are impossible to detect but still extremely harmful</p><p>2) It would soften the lunar dust; lunar dust at present is extremely sharp due to the lack of atmosphere, but a certain amount would drive the dust around a bit, softening it up eventually and making it much less dangerous.</p><p>3) Some protection from radiation.</p><p>4) Some transmission of sound, and flying objects (balloons etc.) would be possible. </p><p>&nbsp;</p><p>Too much atmosphere of course would be an impossible task, and then we couldn't build mass drivers. So the question is, is there a perfect amount of atmosphere? What would be the minimum needed to start to see some of the effects listed above? Note that it doesn't need to be breathable, since the goal is not to terraform. </p> <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>

 

[KosmicHero]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Assuming that we won't be installing a full atmosphere on the moon since it would be gone in a few thousand years and would remove some of the aspects that make the moon attractice (mass drivers, astronomy, etc.), wouldn't it be in our best interest to have a very thin atmosphere?A very thin atmosphere would have the following benefits:1) It would destroy micrometeorites, those of a few mm or cm in diameter that are impossible to detect but still extremely harmful2) It would soften the lunar dust; lunar dust at present is extremely sharp due to the lack of atmosphere, but a certain amount would drive the dust around a bit, softening it up eventually and making it much less dangerous.3) Some protection from radiation.4) Some transmission of sound, and flying objects (balloons etc.) would be possible. &nbsp;Too much atmosphere of course would be an impossible task, and then we couldn't build mass drivers. So the question is, is there a perfect amount of atmosphere? What would be the minimum needed to start to see some of the effects listed above? Note that it doesn't need to be breathable, since the goal is not to terraform. <br />Posted by mithridates</DIV><br /><br />I think that the amount of effort needed to 'install' an atmosphere that would have any of the effects you mentioned would be better invested in other areas. <div class="Discussion_UserSignature"> kosmichero.wordpress.com </div>

 

[mithridates]

<p>How so? Assuming we are colonizing the Moon in the first place we're going to be creating a certain amount of atmosphere while we're at it anyway, in the same way that the Apollo program doubled (I think it was doubled) the amount of atmosphere there during its few trips.</p><p>Though I'm looking more for whether there's a theoretical perfect amount of atmosphere than arguments over whether it's possible or practical in the short term or not. Most discussions about atmosphere centre on the idea of one breathable for us, and with the same atmospheric pressure as Earth, and that of course is wildly impractical. I'm thinking of an extremely thin one, and not necessarily with any oxygen. </p> <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>

 

[neilsox]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Assuming that we won't be installing a full atmosphere on the moon since it would be gone in a few thousand years and would remove some of the aspects that make the moon attractice (mass drivers, astronomy, etc.), wouldn't it be in our best interest to have a very thin atmosphere?A very thin atmosphere would have the following benefits:1) It would destroy micrometeorites, those of a few mm or cm in diameter that are impossible to detect but still extremely harmful2) It would soften the lunar dust; lunar dust at present is extremely sharp due to the lack of atmosphere, but a certain amount would drive the dust around a bit, softening it up eventually and making it much less dangerous.3) Some protection from radiation.4) Some transmission of sound, and flying objects (balloons etc.) would be possible. &nbsp;Too much atmosphere of course would be an impossible task, and then we couldn't build mass drivers. So the question is, is there a perfect amount of atmosphere? What would be the minimum needed to start to see some of the effects listed above? Note that it doesn't need to be breathable, since the goal is not to terraform. <br />Posted by mithridates</DIV><br />The 3 to 6 millibars on Mars produces intense sand storms, but with 1/3 the gravity, the smaller&nbsp;Moon&nbsp;would need as much atmosphere mass&nbsp;as Mars to approximate Mars conditions. Perhaps one millibar would do the things you mentioned, with the possible exception of float balloons. My guess is mass drivers are practical up to about 6 millibars.&nbsp;If the Moon had one millibar of&nbsp; safe to breath oxygen, moon suits could have air compressors instead of oxygen tanks.&nbsp; Neil

 

[mithridates]

Thanks. For the time being then I'll consider one millibar as the ideal. <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>

 

[origin]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Thanks. For the time being then I'll consider one millibar as the ideal. <br />Posted by mithridates</DIV><br /><br />1 millibar????&nbsp; 1/1000 of an atmosphere?&nbsp; 0.0147 psi?&nbsp; Your blood would boil at that pressure.&nbsp; Drawing&nbsp;a vacuum of 1 millibar is a heck of a good vacuum on earth. <div class="Discussion_UserSignature"> </div>

 

[mithridates]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>1 millibar????&nbsp; 1/1000 of an atmosphere?&nbsp; 0.0147 psi?&nbsp; Your blood would boil at that pressure.&nbsp; Drawing&nbsp;a vacuum of 1 millibar is a heck of a good vacuum on earth. <br /> Posted by origin</DIV></p><p>Yes, I know. And your point is? </p> <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>

 

[crazyeddie]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Yes, I know. And your point is? <br /> Posted by mithridates</DIV></p><p>I think his point was that a "moon suit" would still have to be a full-fledged space suit, not just a suit with an air compressor.</p> <div class="Discussion_UserSignature"> </div>

 

[mithridates]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I think his point was that a "moon suit" would still have to be a full-fledged space suit, not just a suit with an air compressor. <br /> Posted by crazyeddie</DIV></p><p>I don't think so. That's what the other person said, not me. I wrote nothing about suits with air compressors, and his post has nothing to do with the topic of suits either. </p> <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>

 

[KosmicHero]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I don't think so. That's what the other person said, not me. I wrote nothing about suits with air compressors, and his post has nothing to do with the topic of suits either. <br />Posted by mithridates</DIV><br /><br />A compressor wouldn't operate at 1 millibar.&nbsp; Like the above post mentioned, a&nbsp;1 millibar vacuum on Earth is good (i.e. you can't pump much more out).</p><p>Your points were radiation protection, micrometerorites, softening of the surface, and sound.&nbsp; Depending on the extent you think these are important (what size micrometerorites, how much sound transmission, how much protection, etc.) the amount of 'atmosphere' becomes impractical.&nbsp; This is true even at lower ranges of these points.</p><p>&nbsp;Two times nothing is still nothing.</p> <div class="Discussion_UserSignature"> kosmichero.wordpress.com </div>

 

[mithridates]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>A compressor wouldn't operate at 1 millibar.&nbsp; Like the above post mentioned, a&nbsp;1 millibar vacuum on Earth is good (i.e. you can't pump much more out).Your points were radiation protection, micrometerorites, softening of the surface, and sound.&nbsp; Depending on the extent you think these are important (what size micrometerorites, how much sound transmission, how much protection, etc.) the amount of 'atmosphere' becomes impractical.&nbsp; This is true even at lower ranges of these points.&nbsp;Two times nothing is still nothing.</DIV></p><p>Thanks, but the whole point of the thread is that I'm asking a question, not here to defend the idea of 1 millibar of atmosphere, nor argue that a compressor would work. If you know at what point micrometeorite and radiation protection + practical sound transmission are possible, by all means let us know. 2 millibars? 6? Is the above poster's view that anything above 6 would make a mass driver impossible correct? Enlighten us. </p><p>As for what size micrometeorites: The answer to this is easy. Any size that we couldn't detect beforehand. </p> <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>

 

[mithridates]

Oh, and to move to a related subject: would a colony in the future eventually have this problem of creating a thin atmosphere where none existed before? A 100 km trip by road here for example gives off 10 kg of CO2. Lunar colonies will be more efficient but in the beginning nobody will be concerned about creating an atmosphere. At what point would this become a problem? <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>

 

[KosmicHero]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Oh, and to move to a related subject: would a colony in the future eventually have this problem of creating a thin atmosphere where none existed before? A 100 km trip by road here for example gives off 10 kg of CO2. Lunar colonies will be more efficient but in the beginning nobody will be concerned about creating an atmosphere. At what point would this become a problem? <br />Posted by mithridates</DIV><br /><br />Firstly I don't think any atmosphere on the moon would be a good.&nbsp; So your answer is zero.&nbsp; This is primarily because the moon is an excellent place for astronomy because there is no atmosphere (light/radio attenuation, weathering, transmission interference, etc.)</p><p>Any 'atmosphere' that was created on the moon wouldn't last very long (my guess).&nbsp; Water which is the likely largest pollutant that we'd create would evaporate or freeze quickly.&nbsp; Much of the dust that we'd kick up would settle and other volatiles would likewise not last. </p><p>An atmosphere that would attenuate meteorites that we can't detect would be nearly as dense (the pressure doesn't really matter) as Earth's.&nbsp; Our ability to detect meteorites is not very sophisticated (esp. on the moon).</p><p>How much sound would you like to transmit?&nbsp; </p> <div class="Discussion_UserSignature"> kosmichero.wordpress.com </div>

 

[mithridates]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Firstly I don't think any atmosphere on the moon would be a good.&nbsp; So your answer is zero.&nbsp; This is primarily because the moon is an excellent place for astronomy because there is no atmosphere (light/radio attenuation, weathering, transmission interference, etc.)Any 'atmosphere' that was created on the moon wouldn't last very long (my guess).&nbsp; Water which is the likely largest pollutant that we'd create would evaporate or freeze quickly.&nbsp; Much of the dust that we'd kick up would settle and other volatiles would likewise not last. An atmosphere that would attenuate meteorites that we can't detect would be nearly as dense (the pressure doesn't really matter) as Earth's.&nbsp; Our ability to detect meteorites is not very sophisticated (esp. on the moon).How much sound would you like to transmit?&nbsp; <br /> Posted by KosmicHero</DIV></p><p>Okay, thanks for the answer. I don't think transmitting sound would be that much of a benefit, just a small one.</p><p>I could see a scenario where eventually environmentalists will start to become concerned about the amount of gases being produced on the moon through colonizing but with their voices drowned out because it would take an awful lot of gas to create any sort of atmosphere (similar to the early 20th century's "but the Earth is so big! No problem!" view on polluting the air), but then there would eventually be a campaign to keep the environment there pristine, with who knows how much success. (this would be in the far future of course)</p><p>Micrometeorites are a worry though. If an atmosphere can't deal with them then it would be quite unsettling to know that any time you could be hit by a rock traveling at several km per second. </p> <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>

 

[qso1]

<p><font color="#800080">How so? Assuming we are colonizing the Moon in the first place we're going to be creating a certain amount of atmosphere while we're at it anyway, in the same way that the Apollo program doubled (I think it was doubled) the amount of atmosphere there during its few trips. Posted by mithridates</font></p><p>Just curious, how did Apollo double the lunar atmosphere?&nbsp;</p> <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[mithridates]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>How so? Assuming we are colonizing the Moon in the first place we're going to be creating a certain amount of atmosphere while we're at it anyway, in the same way that the Apollo program doubled (I think it was doubled) the amount of atmosphere there during its few trips. Posted by mithridatesJust curious, how did Apollo double the lunar atmosphere?&nbsp; <br /> Posted by qso1</DIV></p><p>I can't remember the source, but I think I remember reading that the Moon's atmosphere could fit into something like ten cubic metres if it were as dense as ours, and that the rocket exhaust from the Apollo missions was about the same. </p><p>Oh, found a link:</p><p>http://www.tsgc.utexas.edu/tadp/1995/spects/environment.html</p><p>"Each Apollo mission increased the mass of the lunar atmosphere by about 30%, and it took several weeks for the atmosphere to return to its natural state."</p> <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>

 

[aphh]

How much would 1 millibar of gas weigh on the moon? What would be the most likely source of that gas? Water ice in a shadowed crater that we would nuke to release the gas? <br />

 

[kelvinzero]

<p>&nbsp;haha, thats&nbsp;sort of&nbsp;obscene &nbsp;</p><p>I agree with the majority here that creating any atmosphere would create more problems than it would solve. Also, nitrogen,&nbsp;carbon and hydrogen would be as valuable as gold on the moon. No way would we throw it away if we could avoid it.</p><p>&nbsp;However it does raise the interesting (to me anyway) question: Would a large scale industry on the moon polute it with an atmosphere? It sounds like it could create enough to mess with scientific measurements at least. Would there be enough to create more direct problems even if we were doing whatever was practical to avoid releasing valuable gasses?</p>

 

[yevaud]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I can't remember the source, but I think I remember reading that the Moon's atmosphere could fit into something like ten cubic metres if it were as dense as ours, and that the rocket exhaust from the Apollo missions was about the same. Oh, found a link:http://www.tsgc.utexas.edu/tadp/1995/spects/environment.html&quot;Each Apollo mission increased the mass of the lunar atmosphere by about 30%, and it took several weeks for the atmosphere to return to its natural state." <br /> </p><p>Posted by <em>Mithridates</em></DIV></p><p>Indeed, there is an atmosphere:&nbsp; http://findarticles.com/p/articles/mi_m1200/is_n24_v148/ai_17909344</p><p>[Mike Mendillo was one of my Professors; Jeff Baumgartner was the Department Sysadmin] </p> <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>

 

[derekmcd]

If I was a moon colonist, I'd prefer as little atmosphere as possible.&nbsp; It would significantly cut down my slice off the tee. <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-laughing.gif" border="0" alt="Laughing" title="Laughing" /><br /> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>If I was a moon colonist, I'd prefer as little atmosphere as possible.&nbsp; It would significantly cut down my slice off the tee. <br />Posted by derekmcd</DIV></p><p>lBut you might have a tendancy to consistently overdrive the "green" (the putting surface ought to be real interesting).<br /></p> <div class="Discussion_UserSignature"> </div>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>lBut you might have a tendancy to consistently overdrive the "green" (the putting surface ought to be real interesting). <br /> Posted by DrRocket</DIV></p><p>At least I wouldn't be losing it in the trees all the time...&nbsp;</p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[yevaud]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>At least I wouldn't be losing it in the trees all the time...&nbsp; </p><p> Posted by <em>derekmcd</em></DIV><br /></p><p>Yes, but some of those traps are just <em>killer</em>. </p> <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>