page_title: Space colonization
section_title: Lagrange points
hierarchical_section_title: Space colonization / Location / Near-Earth space / Lagrange points
caption_attribution_description: A (not drawn to scale!) contour plot of the effective potential of a two-body system. (the Sun and Earth here), showing the 5 Lagrange points. An object orbiting in free-fall could trace out a contour (such as the Moon, shown).
context_page_description: Space colonization is permanent human habitation and exploitation of natural resources off the planet Earth.
  Many arguments have been made for and against space colonization. The two most common in favor of colonization are survival of human civilization and the biosphere in the event of a planetary-scale disaster, and the availability of additional resources in space that could enable expansion of human society. The most common objections to colonization include concerns that the commodification of the cosmos may be likely to enhance the interests of the already powerful, including major economic and military institutions, and to exacerbate pre-existing detrimental processes such as wars, economic inequality, and environmental degradation.
  No space colonies have been built so far. Currently, the building of a space colony would present a set of huge technological and economic challenges. Space settlements would have to provide for nearly all the material needs of hundreds or thousands of humans, in an environment out in space that is very hostile to human life.
context_section_description: Another near-Earth possibility are the five Earth–Moon Lagrange points. Although they would generally also take a few days to reach with current technology, many of these points would have near-continuous solar power because their distance from Earth would result in only brief and infrequent eclipses of light from the Sun. However, the fact that the Earth–Moon Lagrange points L₄ and L₅ tend to collect dust and debris, whereas L₁-L₃ require active station-keeping measures to maintain a stable position, make them somewhat less suitable places for habitation than was originally believed. Additionally, the orbit of L₂–L₅ takes them out of the protection of the Earth's magnetosphere for approximately two-thirds of the time, exposing them to the health threat from cosmic rays.
  The five Earth–Sun Lagrange points would totally eliminate eclipses, but only L₁ and L₂ would be reachable in a few days' time. The other three Earth–Sun points would require months to reach.
caption: A contour plot of the gravitational potential of the Sun and Earth, showing the five Earth–Sun Lagrange points
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