A number of commercial ventures have been founded in the 21st century with the goal of mining various asteroids and comets in the solar system for commercial purposes.

There are a number of valuable resources that could in principle be harvested from these objects, including gold, iridium, silver, osmium, palladium, platinum, rhenium, rhodium, ruthenium and tungsten for transport back to Earth; iron, cobalt, manganese, molybdenum, nickel, aluminium, and titanium for space-based construction. Perhaps the most immediately useful resource may be water, which could be converted into hydrogen and oxygen to fuel spacecraft.

Some identified asteroids are believed to be quite rich in minerals. Indeed, if one were to look up current prices on the London Metal Exchange for these resources and assume (quite wrongly, of course) that the price would hold up in the event that asteroid mining became practical and economical, there are many individual asteroids whose value far exceeds 100 trillion US dollars. As of September 2016, there were 711 known asteroids with a computed value exceeding US$100 trillion.

Some nations are beginning to promulgate legal regimes for extraterrestrial resource extraction. For example, the United States "SPACE Act of 2015," facilitating private development of space resources consistent with US international treaty obligations, passed the US House of Representatives in July 2015. In November 2015 it passed the United States Senate.

On 25 November, US President Barack Obama signed the H.R.2262 – U.S. Commercial Space Launch Competitiveness Act into law. The law recognizes the right of U.S. citizens to own space resources they obtain and encourages the commercial exploration and utilization of resources from asteroids.

According to the article § 51303 of the law: "A United States citizen engaged in commercial recovery of an asteroid resource or a space resource under this chapter shall be entitled to any asteroid resource or space resource obtained, including to possess, own, transport, use, and sell the asteroid resource or space resource obtained in accordance with applicable law, including the international obligations of the United States."

In February 2016, the Government of Luxembourg announced that it would attempt to "jump-start an industrial sector to mine asteroid resources in space" by, among other things, creating a "legal framework" and regulatory incentives for companies involved in the industry. By June 2016, it announced that it would "invest more than US$200 million in research, technology demonstration, and in the direct purchase of equity in companies relocating to Luxembourg." In 2017, it became the "first European country to pass a law conferring to companies the ownership of any resources they extract from space", and remained active in advancing space resource public policy in 2018.

Some have suggested that the first trillionaire(s) will be created by the space mining industry.