As the demands for important metal resources continue to rise, there is an increased interest in studying various space environments that may provide alternative reservoirs. Currently, it is thought that certain groups of asteroids could contain significant abundances of metals such as copper, iron, nickel, or cobalt. However, traditional mining practices on Earth typically require extensive chemical processing, which raises a concern regarding the feasibility of mining resources in space. How can we reliably identify individual asteroids as rich in metal resources, and how can metals be effectively extracted in ways that minimize cost and destruction to the local environment?

A recent study by Katarzyna Łuszczek at the Wrocław University of Science and Technology and Agata Krzesińska at the University of Oslo sought to better identify potential space resources by understanding how metals, such as copper, can be concentrated on asteroids. To do this, several meteorites called ordinary chondrites, thought to come from common S-type, stony asteroids, were analyzed for their copper content. Copper abundance was then correlated with features in each meteorite that could indicate impact shock effects and/or melting. The study concluded that residual heat generated from collisional impact events likely drives the formation of pure copper deposits, as well as other reactions, in ordinary chondrites. The study referred to the region in which this occurs as a “shock darkening zone,” and it can be identified using remote spectroscopic techniques. Therefore, the study suggested that the shock zones can be used to find where pure copper was deposited, which is easier to mine than copper in other metal alloys. Thus, while it might not be environmentally or economically feasible to mine an entire asteroid for metals like copper, specific regions that exhibit shock darkening might be more lucrative and serve as more accessible reservoirs for metal resources in the future. READ MORE