# What would a moon have to be made of to make it worth mining? **URL:** \ **Category:** Factual Questions\ **Created:** [October 25, 2012, 1:12am UTC](https://boards.straightdope.com/t/what-would-a-moon-have-to-be-made-of-to-make-it-worth-mining/638783 "2012-10-25T01:12:42Z")\ **Posts on this page:** 14\ **Page:** 4
**Author:** ![outlierrn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/outlierrn/32/3005_2.png) [@outlierrn](https://boards.straightdope.com/u/outlierrn)\ **Post date:** [October 26, 2012, 6:17pm UTC](https://boards.straightdope.com/t/what-would-a-moon-have-to-be-made-of-to-make-it-worth-mining/638783/61 "2012-10-26T18:17:02Z")
> [@eburacum45](#): > > Once there is sufficient industrial infrastructure on the Moon, building ships from lunar materials would be cheaper than lifting them up from the Earth. By building large numbers of spacecraft using lunar materials we could gain access to the resources of the other moons and planets - not to bring them all back to Earth, but to use them to support a population in space. The Lunar branch of the Environmental Protection Agency would be happy to review your proposal for the removal of additional mass at it’s earliest convenience. Serious question: How deep, in miles say, is the Earth’s gavity well? ---
**Author:** ![Grey](https://avatars.discourse-cdn.com/v4/letter/g/b782af/32.png) [@Grey](https://boards.straightdope.com/u/Grey)\ **Post date:** [October 26, 2012, 6:31pm UTC](https://boards.straightdope.com/t/what-would-a-moon-have-to-be-made-of-to-make-it-worth-mining/638783/62 "2012-10-26T18:31:42Z")
Well it reaches the moon obviously. ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [October 26, 2012, 7:14pm UTC](https://boards.straightdope.com/t/what-would-a-moon-have-to-be-made-of-to-make-it-worth-mining/638783/63 "2012-10-26T19:14:40Z")
> [@outlierrn](#): > > Serious question: How deep, in miles say, is the Earth’s gavity well? The furthest practical extent of the Earth’s gravitational influence might be best described by its Trojan libration (LaGrangian) points L4 and L5, where, if I read correctly, at least one asteroid resides. These points are where the sun’s gravity exactly balances the Earth’s gravity, at 60 degrees leading and trailing in Earth’s orbital path, which places them at more than 90 million miles away. Gravity follows the inverse square law, so it falls off at a rate of the square of the distance from the gravitational focus, so “how deep” is kind of not a meaningful question. ---
**Author:** ![Enderw24](https://avatars.discourse-cdn.com/v4/letter/e/ba9def/32.png) [@Enderw24](https://boards.straightdope.com/u/Enderw24)\ **Post date:** [October 26, 2012, 7:38pm UTC](https://boards.straightdope.com/t/what-would-a-moon-have-to-be-made-of-to-make-it-worth-mining/638783/64 "2012-10-26T19:38:52Z")
I was going to say saffron or white truffles, but even at $5,000/lbs and $6,000/lbs respectively, it’s not worth going up to the moon for. Would have said platinum too, but, strangely, gold is currently selling for more. But even if it were worth it at ~$1,800/oz you run into another problem. New mine production totals approximately only five million troy ounces a year. So that’s ~ $9.5 billion dollars worth of platinum you could mine from the moon…while simultaneously doubling Earth’s supply and thus halving your expected value. In other words, you’d earn ~$4.75 billion gross off your platinum. Maybe not worth it. Same with gold. Independently, I found that same website linked to above which makes the case for trying to mine LSD. But I can’t imagine the global market for moon-based LSD would be worth the trip to mine it. Seriously, is current demand/production of LSD that far askew that we’d need a couple million more pounds of it? Antimatter is also listed but I dispute the notion of that. It’s priced based upon the amount created vs the price to create it. Which is fine and all, but there’s no real market for it at this point, and, if there were, nobody could afford the trillion dollar/pound price tag anyway. So I’m going to have to go with diamonds. It has enough demand from both commercial use and consumer use that a large supply won’t depress the market. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [October 26, 2012, 8:09pm UTC](https://boards.straightdope.com/t/what-would-a-moon-have-to-be-made-of-to-make-it-worth-mining/638783/65 "2012-10-26T20:09:38Z")
> [@For You](#): > > The furthest practical extent of the Earth’s gravitational influence might be best described by its Trojan libration (LaGrangian) points L4 and L5, where, if I read correctly, at least one asteroid resides. These points are where the sun’s gravity exactly balances the Earth’s gravity, at 60 degrees leading and trailing in Earth’s orbital path, which places them at more than 90 million miles away. > > Gravity follows the inverse square law, so it falls off at a rate of the square of the distance from the gravitational focus, so “how deep” is kind of not a meaningful question. Right. The more meaningful question, is how fast does something have to be moving—relative to earth—for the earth’s gravity not to overcome its own motion. From the earth’s surface, this is ~25,000 mph. And this escape velocity would fall off at the inverse square the further away something is (double the distance, 4x less strong. Triple the distance, 9x less strong. Quadruple the distance, 16x less strong, etc.). But of course there’s all sorts of gravitational bodies in the vicinity mucking things up a bit. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 26, 2012, 8:09pm UTC](https://boards.straightdope.com/t/what-would-a-moon-have-to-be-made-of-to-make-it-worth-mining/638783/66 "2012-10-26T20:09:50Z")
> [@](#): > > Quoth **Dinsdale** : > > He’s big on exploitation of Lagrange points, and pissed that the ISS was not sited at one. Science fiction writers have seriously hyped up the notion of putting things at Lagrange points, but really, there usually isn’t any good reason to do so. The Earth-Sun L1 and L2 points have their uses (for things that need to always be able to see the Sun or the lit portion of the Earth, for L1, or things that need to always remain in shadow for L2), but none of the other Earth-Sun points are useful for anything, nor are any of the Earth-Moon points. In fact, the L4 and L5 points of any given system are _worse_ places for satellites than any old random orbit, since they tend to accumulate a bunch of crud that could collide with your satellite. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [October 26, 2012, 8:14pm UTC](https://boards.straightdope.com/t/what-would-a-moon-have-to-be-made-of-to-make-it-worth-mining/638783/67 "2012-10-26T20:14:48Z")
> [@Dinsdale](#): > > All right, now we got the kid thinking about this, neglecting his work undoubtedly, and sending me texts. The latest (which I’m not sure I entirely understand): > > **An interesting idea for asteroid mining would be to establish orbital depots for H2-LOX fuel and sell that to interplanetary missions. That would greatly increase the mass/decrease the cost of interplanetary missions, if the cost of mining/producing the fuel is less than about $10k/kg.** > > He’s big on exploitation of Lagrange points, and pissed that the ISS was not sited at one. Oh yeh. He’s talking about stations in space for refining liquid hydrogen and oxygen for chemically fueled thrusters. Basically gas stations in space/interplanetary trucking and refueling. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [October 26, 2012, 8:50pm UTC](https://boards.straightdope.com/t/what-would-a-moon-have-to-be-made-of-to-make-it-worth-mining/638783/68 "2012-10-26T20:50:08Z")
> [@Chronos](#): > > Science fiction writers have seriously hyped up the notion of putting things at Lagrange points, but really, there usually isn’t any good reason to do so. The Earth-Sun L1 and L2 points have their uses (for things that need to always be able to see the Sun or the lit portion of the Earth, for L1, or things that need to always remain in shadow for L2), but none of the other Earth-Sun points are useful for anything, nor are any of the Earth-Moon points. In fact, the L4 and L5 points of any given system are _worse_ places for satellites than any old random orbit, since they tend to accumulate a bunch of crud that could collide with your satellite. Well, there is the proposed [Exploration Gateway Platform](http://en.wikipedia.org/wiki/Exploration_Gateway_Platform) by Boeing using the Earth-Moon L1 and/or L2 points for just such an idea of being used as refueling/servicing depots. ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [October 26, 2012, 10:17pm UTC](https://boards.straightdope.com/t/what-would-a-moon-have-to-be-made-of-to-make-it-worth-mining/638783/69 "2012-10-26T22:17:35Z")
> [@Incubus](#): > > Unobtainium? You know, some sort of wonder material? If it had applications in space travel, we could mine it using conventional materials, until we could construct unobtainium mining equipment which would greatly increase productivity. That’s what they called the metal being mined on Pandora in Avatar, valued at $20 million per kilo. Larry Niven also suggested mining the asteroids for magnetic monopoles, which were critically useful for star drives and other high-energy applications. Back in the real world, I’m thinking the only thing we’re going to find to mine worth going there for are the necessary materials to sustain a space colony and build more ships: once a moon colony is truly self-sustaining, it will be easier to launch ships to the outer system from there rather than from Earch due to the depth of the gravity well. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [October 26, 2012, 10:32pm UTC](https://boards.straightdope.com/t/what-would-a-moon-have-to-be-made-of-to-make-it-worth-mining/638783/70 "2012-10-26T22:32:52Z")
On second thought: Boobies or saffron. Or both. Or just boobies. ---
**Author:** ![toadspittle](https://avatars.discourse-cdn.com/v4/letter/t/c0e974/32.png) [@toadspittle](https://boards.straightdope.com/u/toadspittle)\ **Post date:** [October 26, 2012, 11:13pm UTC](https://boards.straightdope.com/t/what-would-a-moon-have-to-be-made-of-to-make-it-worth-mining/638783/71 "2012-10-26T23:13:55Z")
> [@cmyk](#): > > On second thought: > > Boobies or saffron. Or both. > Or just boobies. But porn is aleady free on the internet! Or is this some new kind of SPACE PORN? ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [October 26, 2012, 11:58pm UTC](https://boards.straightdope.com/t/what-would-a-moon-have-to-be-made-of-to-make-it-worth-mining/638783/72 "2012-10-26T23:58:52Z")
> [@Ethilrist](#): > > That’s what they called the metal being mined on Pandora in Avatar, valued at $20 million per kilo. The movie knowingly used the term as a joke, because unobtainium has long referred to the plethora of magical materials in science fiction. It’s apparently been around since the 1950s. > [@](#): > > “unobtainium, n. A substance having the exact high test properties required for a piece of hardware or other item of use, but not obtainable either because it theoretically cannot exist or because technology is insufficiently advanced to produce it. Humorous or ironical.” Listed in “Interim Glossary, Aero-Space Terms,” as compiled by Woodford Heflin and published in February, 1958, by the Air University of the US Air Force. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [October 27, 2012, 12:21am UTC](https://boards.straightdope.com/t/what-would-a-moon-have-to-be-made-of-to-make-it-worth-mining/638783/73 "2012-10-27T00:21:44Z")
> [@toadspittle](#): > > But porn is aleady free on the internet! Or is this some new kind of SPACE PORN? You have NO idea. Plus, space saffron? To die for. ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [October 27, 2012, 12:24am UTC](https://boards.straightdope.com/t/what-would-a-moon-have-to-be-made-of-to-make-it-worth-mining/638783/74 "2012-10-27T00:24:31Z")
> [@Exapno\_Mapcase](#): > > The movie knowingly used the term as a joke, because unobtainium has long referred to the plethora of magical materials in science fiction. > > It’s apparently been around since the 1950s. Yep. Old joke. Shit, even that crappy movie The Core beat Avatar to the joke on film, when the designer of the ship said he created a new, amazing metal alloy he named Unobtainium… _snicker, snicker._ [Previous page](https://boards.straightdope.com/t/what-would-a-moon-have-to-be-made-of-to-make-it-worth-mining/638783.md?page=3)