Asteroid mining is the process of extracting valuable materials from relatively small and dense bodies orbiting the Sun known as asteroids. While the process has been studied and speculated about for a long time, it is an endeavor that has yet to come to fruition. Numerous technical, financial, and legal challenges must be overcome in order to move asteroid mining out of the realm of science fiction and into scientific reality.
Astronomical study of asteroids through telescopic spectroscopy involves analyzing light that is reflected from their surfaces. Different materials absorb and reflect light at different frequencies, and each material has a spectroscopic signature by which it can be identified. Based on the results of research though telescopic spectroscopy, scientists believe that asteroids are composed of a number of valuable minerals.
Some of these minerals are relatively common, such as iron and nickel. Others are likely rarer, such as gold and platinum. The wealth of materials locked up in asteroids is one tantalizing reason that plans for asteroid mining have been in development for decades. It remains to be seen, however, how the process can be made cost-effective enough for this to be practical.
Colonization of space is another motivation for development of asteroid mining. Breaking free of the Earth’s gravity is a very energy-intensive and expensive task. It would be impractical to develop a substantial human presence in space by forever transporting all the necessary resources to do so from Earth. At some point, colonists are expected to utilize extraterrestrial resources to manufacture what they need to live in space. Asteroid mining is one potential way they might get the raw materials they need.
While possible ways of extracting resources from asteroids have been and continue to be researched extensively, asteroid mining in practice is likely still far off. Technical challenges such as reliable transportation, living arrangements while mining, and how to extract materials in low gravity environments must still be solved. International legal agreements such as the Outer Space Treaty and domestic legal regulations in different countries also stand in the way of asteroid mining. It is not clear by what economic model these resources might be utilized given the legal limitations on their use. Legal uncertainty regarding ownership of resources extracted limits those who are wary about investing without clearly established claim to the fruits a given venture.
Even though mining asteroids is not yet a scientific reality, it is featured extensively in science fiction works. These include Isaac Asimov’s short story "Catch That Rabbit," which is included in his I, Robot collection and Robert Heinlein’s novel The Rolling Stones. Other notable science fiction authors as Poul Anderson, C. J. Cherryh, Ben Bova, and more have also published stories and novels featuring asteroid mining. These types of works, while fictional, may serve as a creative outlet for thought experiments that could ultimately influence real life development of mining asteroids.