Colonization of the asteroids
Encyclopedia
The asteroid
s have long been suggested as possible sites for human colonization. This idea is popular in science fiction
. Asteroid mining
, a proposed industrial process in which asteroids are mined for valuable materials, especially platinum group
metals, may be automated or require a crew to remain at the target asteroid.
Some C-type asteroid
s are likely carbonaceous chondrite
s, which are some tens of percent water by mass.
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
s have long been suggested as possible sites for human colonization. This idea is popular in science fiction
Science fiction
Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...
. Asteroid mining
Asteroid mining
Asteroid mining refers to the possibility of exploiting raw materials from asteroids and planetoids in space, including near-Earth objects. Minerals and volatiles could be mined from an asteroid or spent comet to provide space construction material , to extract water and oxygen to sustain the lives...
, a proposed industrial process in which asteroids are mined for valuable materials, especially platinum group
Platinum group
The platinum group metals is a term used sometimes to collectively refer to six metallic elements clustered together in the periodic table.These elements are all transition metals, lying in the d-block .The six...
metals, may be automated or require a crew to remain at the target asteroid.
Advantages
- Low gravity greatly reduces the cost and risk of "landing" compared to the much deeper gravity wells of the MoonMoonThe Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
or MarsMarsMars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...
, and simplifies construction technologies (such as craneCrane (machine)A crane is a type of machine, generally equipped with a hoist, wire ropes or chains, and sheaves, that can be used both to lift and lower materials and to move them horizontally. It uses one or more simple machines to create mechanical advantage and thus move loads beyond the normal capability of...
s) and reduces structural strength requirements - Large number of possible sites, with over 300,000 asteroids identified to date
- Asteroids' chemical composition varies (see asteroid spectral typesAsteroid spectral typesAsteroids are assigned a type based on spectral shape, color, and sometimes albedo. These types are thought to correspond to an asteroid's surface composition...
), providing a variety of materials usable in building and fuelingIn-Situ Resource UtilizationIn space exploration, in-situ resource utilization describes the proposed use of resources found or manufactured on other astronomical objects to further the goals of a space mission....
spacecraftSpacecraftA spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....
and space habitats. The Trojan asteroidTrojan asteroidThe Jupiter Trojans, commonly called Trojans or Trojan asteroids, are a large group of objects that share the orbit of the planet Jupiter around the Sun. Relative to Jupiter, each Trojan librates around one of the planet's two Lagrangian points of stability, and , that respectively lie 60° ahead...
s, in JupiterJupiterJupiter is the fifth planet from the Sun and the largest planet within the Solar System. It is a gas giant with mass one-thousandth that of the Sun but is two and a half times the mass of all the other planets in our Solar System combined. Jupiter is classified as a gas giant along with Saturn,...
's orbit, may be primarily extinct comets. - Some Earth-crossing asteroids require less energy (delta-VDelta-vIn astrodynamics a Δv or delta-v is a scalar which takes units of speed. It is a measure of the amount of "effort" that is needed to change from one trajectory to another by making an orbital maneuver....
) to reach from Earth than the MoonMoonThe Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
. - Material mined from asteroidsAsteroid miningAsteroid mining refers to the possibility of exploiting raw materials from asteroids and planetoids in space, including near-Earth objects. Minerals and volatiles could be mined from an asteroid or spent comet to provide space construction material , to extract water and oxygen to sustain the lives...
could be a basis for a trade economy, and precious metals may even be returned to Earth or other colonized worlds from asteroid minesAsteroid miningAsteroid mining refers to the possibility of exploiting raw materials from asteroids and planetoids in space, including near-Earth objects. Minerals and volatiles could be mined from an asteroid or spent comet to provide space construction material , to extract water and oxygen to sustain the lives...
for economic gain. - High surface/volume ratio enables effective exploration and exploitation of mineral resources and provides maximal portion of useful building ground on the surface and interior.
- High vacuum and low gravity would facilitate the evolution of some hi-tech industries such as material engineering and physical electronics (crystal growth, epitaxyEpitaxyEpitaxy refers to the deposition of a crystalline overlayer on a crystalline substrate, where the overlayer is in registry with the substrate. In other words, there must be one or more preferred orientations of the overlayer with respect to the substrate for this to be termed epitaxial growth. The...
). - Many asteroids (especially the extinct comet cores) contain large amounts (more than 5% of total composition) of water and other volatilesVolatilesIn planetary science, volatiles are that group of chemical elements and chemical compounds with low boiling points that are associated with a planet's or moon's crust and/or atmosphere. Examples include nitrogen, water, carbon dioxide, ammonia, hydrogen, and methane, all compounds of C, H, O...
, as well as carbonCarbonCarbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
, which are all necessary for life support. - Isaac AsimovIsaac AsimovIsaac Asimov was an American author and professor of biochemistry at Boston University, best known for his works of science fiction and for his popular science books. Asimov was one of the most prolific writers of all time, having written or edited more than 500 books and an estimated 90,000...
pointed out the advantage of building cities inside hollowed out asteroids, since the volume of all the asteroids put together is a great deal more than that of a mile-high building covering the EarthEarthEarth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
would be, and thus could accommodate a large populationPopulationA population is all the organisms that both belong to the same group or species and live in the same geographical area. The area that is used to define a sexual population is such that inter-breeding is possible between any pair within the area and more probable than cross-breeding with individuals...
.
Disadvantages
- Low gravity. Humans would have to adapt, or some form of artificial gravityArtificial gravityArtificial gravity is the varying of apparent gravity via artificial means, particularly in space, but also on the Earth...
would have to be implemented. - Most asteroids are far from the Sun. The main asteroid belt is roughly 2 to 4 times further from the Sun than Earth. This means that the available solar energy (solar constantSolar constantThe solar constant, a measure of flux density, is the amount of incoming solar electromagnetic radiation per unit area that would be incident on a plane perpendicular to the rays, at a distance of one astronomical unit...
) is 4 to 16 times less, although building large reflectors to collect sunlight is possible in space. - Many asteroids may merely be loose agglomerations of dust and rocks, which may be very difficult to use.
- Asteroids are vulnerable to Solar radiation, lacking similarities like Earth's ozone layerOzone layerThe ozone layer is a layer in Earth's atmosphere which contains relatively high concentrations of ozone . This layer absorbs 97–99% of the Sun's high frequency ultraviolet light, which is potentially damaging to the life forms on Earth...
and magnetosphereMagnetosphereA magnetosphere is formed when a stream of charged particles, such as the solar wind, interacts with and is deflected by the intrinsic magnetic field of a planet or similar body. Earth is surrounded by a magnetosphere, as are the other planets with intrinsic magnetic fields: Mercury, Jupiter,...
(though some may have a magnetic field, they are bound to be considerably weaker by comparison). Shielding with several meters of asteroidal regolith is a trivial solution to this problem. - Asteroids have no or very little atmosphere.
- Smaller objects may collide with the asteroid and cause significant damage.
Asteroids of special interest
- (6178) 1986 DA(6178) 1986 DA1986 DA is a 2.3-kilometre-diameter M-type Mars-crosser and near-Earth asteroid, notable for being significantly more radar-reflective than other asteroids...
is a potentially metallic near-Earth asteroid. - 216 Kleopatra216 Kleopatra216 Kleopatra is a trinary main-belt asteroid that was discovered by Johann Palisa on April 10, 1880, in Pola. It is named after Cleopatra, Queen of Ancient Egypt....
is a metallic main-belt asteroid.
Some C-type asteroid
C-type asteroid
C-type asteroids are carbonaceous asteroids. They are the most common variety, forming around 75% of known asteroids, and an even higher percentage in the outer part of the asteroid belt beyond 2.7 AU, which is dominated by this asteroid type...
s are likely carbonaceous chondrite
Carbonaceous chondrite
Carbonaceous chondrites or C chondrites are a class of chondritic meteorites comprising at least 7 known groups and many ungrouped meteorites. They include some of the most primitive known meteorites...
s, which are some tens of percent water by mass.
Asteroid colonies in science fiction
- See Asteroids in fiction.
See also
- Space colonizationSpace colonizationSpace colonization is the concept of permanent human habitation outside of Earth. Although hypothetical at the present time, there are many proposals and speculations about the first space colony...
- Solar SystemSolar SystemThe Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...