>I intuitively suspect, without doing any numbers, that no matter how much nitrogen and oxygen you could theoretically scrounge up, there won’t be enough gravit

>I intuitively suspect, without doing any numbers, that no matter how much nitrogen and oxygen you could theoretically scrounge up, there won’t be enough gravity to make air pressure high enough to be of any use to human life. Since mass can only increase gravity, I think that must be wrong regardless of specific numbers. I guess the same amount of nitrogen, etc. as is in a column of atmosphere on earth would have to weigh less, but that's not a constraint. There can be more! In support of this, here is a similar question on stackexchange: https://worldbuilding.stackexchange.com/questions/26639/how-to-blanket-moon-with-a-permanent-atmosphere https://worldbuilding.stackexchange.com/questions/26639/how-... In my opinion, (because it agrees with my prejudices) the best answer is not the accepted one and is at the bottom of the page (Foskey). "It is also incorrect to say that the atmosphere could never be thick enough to breathe. Titan has a surface gravity similar to the moon, and has an atmosphere thicker than the earth's. Because the gravity is less, it takes a higher column of air to achieve that pressure, but it can be achieved." "Part of the reason Titan has been able to retain that atmosphere over the history of the solar system is that it is much colder than the moon, and is less affected by the solar wind since it's much farther from the sun. But, again, time scales matter. I have not found a source estimating the exact timeframe for atmospheric loss, but I recall reading that it would take thousands of years or more." There is also a link to this essay: https://slate.com/technology/2014/07/terraforming-the-moon-it-would-be-a-lot-like-florida.html https://slate.com/technology/2014/07/terraforming-the-moon-i...