Colonization of the asteroid belt

Asteroids, including those in the asteroid belt, have been suggested as possible sites of space colonization.^[1] Motives include the survival of humanity, and the specific economic opportunity for asteroid mining. Obstacles include transportation distance, temperature, radiation, lack of gravity, and psychological issues.

Most asteroids have minerals that could be mined. Because these bodies do not have substantial gravity wells, only a low delta-V is needed to haul materials to a construction site.^[2][3] There is estimated to be enough material in the main asteroid belt alone to build enough space habitats to equal the habitable surface area of 3,000 Earths.^[4]

The asteroid belt has about 10¹⁸ metric tonnes of overall material available – ten thousand times more than is available in the near-Earth asteroids^[5] – but it is thinly distributed as it covers a vast region of space. The largest asteroid is Ceres, which at about 940 km in diameter is big enough to be a dwarf planet. The next two largest are Pallas and Vesta, both about 520 km in diameter. Uncrewed supply craft should be practical with little technological advance, even crossing 500 million kilometers of space. The colonists would have a strong interest in assuring their asteroid did not hit Earth or any other body of significant mass, but would have extreme difficulty in moving an asteroid^{[citation needed]} of any size. The orbits of the Earth and most asteroids are very distant from each other in terms of delta-v and the asteroidal bodies have enormous momentum. Rockets or mass drivers can perhaps be installed on asteroids to direct their path into a safe course.