Editing Space colonization (section)

====Raw materials====
Colonies on the Moon, Mars, asteroids, or the metal-rich planet [[Mercury (planet)|Mercury]], could extract local materials. The Moon is deficient in [[Volatile (astrogeology)|volatiles]] such as [[argon]], [[helium]] and compounds of [[carbon]], [[hydrogen]] and [[nitrogen]]. The LCROSS impacter was targeted at the [[Cabeus (crater)|Cabeus crater]] which was chosen as having a high concentration of water for the Moon. A plume of material erupted in which some water was detected. Mission chief scientist Anthony Colaprete estimated that the Cabeus crater contains material with 1% water or possibly more.<ref>{{Cite news | url=http://www.sfgate.com/science/article/NASA-s-moon-blast-called-a-smashing-success-3213973.php | work=The San Francisco Chronicle | first=David | last=Perlman | title=NASA's moon blast called a smashing success | date=10 October 2009 | access-date=19 July 2015 | archive-url=https://web.archive.org/web/20150721235224/http://www.sfgate.com/science/article/NASA-s-moon-blast-called-a-smashing-success-3213973.php | archive-date=21 July 2015 | url-status=live }}</ref> Water [[ice]] should also be in other permanently shadowed craters near the lunar poles. Although helium is present only in low concentrations on the Moon, where it is deposited into [[regolith]] by the solar wind, an estimated million tons of He-3 exists over all.<ref>{{cite web|title=The Second Moon Race: It's the USA vs. China vs. India vs. ... Nigeria?|url=http://www.satnews.com/stories2007/4588/ |archive-url= https://web.archive.org/web/20120308151604/http://www.satnews.com/stories2007/4588/|archive-date=8 March 2012}}</ref> It also has industrially significant [[oxygen]], [[silicon]], and metals such as [[iron]], [[aluminium]], and [[titanium]].

Launching materials from Earth is expensive, so bulk materials for colonies could come from the Moon, a [[near-Earth object]] (NEO), [[Phobos (moon)|Phobos]], or [[Deimos (moon)|Deimos]]. The benefits of using such sources include: a lower gravitational force, no [[Drag (physics)|atmospheric drag]] on cargo vessels, and no biosphere to damage. Many NEOs contain substantial amounts of metals. Underneath a drier outer crust (much like [[oil shale]]), some other NEOs are inactive comets which include billions of tons of water ice and [[kerogen]] hydrocarbons, as well as some nitrogen compounds.<ref>{{cite conference |title=Discovery of Abundant, Accessible Hydrocarbons nearly Everywhere in the Solar System |last1= Zuppero|first1= Anthony |year= 1996 |publisher= [[American Society of Civil Engineers|ASCE]] |book-title= Proceedings of the Fifth International Conference on Space '96 |doi= 10.1061/40177(207)107|isbn= 0-7844-0177-2}}</ref>

Farther out, [[Colonization of the outer Solar System#Jupiter trojans|Jupiter's Trojan asteroids]] are thought to be rich in water ice and other volatiles.<ref>{{Cite news|last=Sanders|first=Robert|title=Binary asteroid in Jupiter's orbit may be icy comet from solar system's infancy|date=1 February 2006|publisher=UC Berkeley|url=http://www.berkeley.edu/news/media/releases/2006/02/01_patroclus.shtml|access-date=25 May 2009|archive-url=https://web.archive.org/web/20181211102116/https://www.berkeley.edu/news/media/releases/2006/02/01_patroclus.shtml|archive-date=11 December 2018|url-status=live}}</ref>

[[Recycling]] of some raw materials would almost certainly be necessary.