A few years ago, asteroid mining was all the rage. With the commercial space sector growing rapidly, the dream of commercializing space seemed almost imminent. Essentially, the idea of having platforms and spacecraft that could assemble and mine near-Earth asteroids (NEAs) and then return them to space-based foundries was akin to sending commercial crews to Mars. After much speculation and failed ventures, these plans were put on hold until the technology matured and other milestones could first be achieved.
Nevertheless, the dream of asteroid mining and the associated “post-scarcity” future remains. In addition to the need for more infrastructure and technical development, further research is needed to determine the chemical composition of small asteroids. In a recent study, a team led by researchers at the Institute of Space Sciences (ICE-CSIC) analyzed samples of C-type (carbon-rich) asteroids, which make up 75% of known asteroids. Their results show that these asteroids could be a crucial source of raw materials and offer opportunities for future resource exploitation.
The team was led by Dr. Josep M. Trigo-Rodríguez, a theoretical physicist from the Institute of Space Sciences (ICE) and the Catalonian Institute for Space Studies (IEEC) in Barcelona. He was joined by PhD student Pau Grèbol-Tomàs (also from ICE and IEEC), Dr in the *Monthly Communications of the Royal Astronomical Society* (MNRAS).
Reflected light image of a thin section of a carbonaceous chondrite meteorite from NASA’s Antarctic collection. Image credit: ICE-CSIC/JMTrigo-Rodríguez et al. (2025)
Carbonaceous chondrites (C-chondrites) regularly fall to Earth but are rarely recovered by scientists for study. Aside from making up only 5% of all meteorites, their fragility often causes them to shatter and be lost. To date, the majority of specimens found have been found in desert regions, including the Sahara and Antarctica. The Asteroids, Comets and Meteorites Research Group at ICE-CSIC, led by Trigo-Rodriguez, studies the physicochemical properties of asteroids and comets and is the international archive for NASA’s Antarctic meteorite collection.
In this latest study, the research group selected and characterized the asteroid samples, which were then analyzed using mass spectrometry by Professor Jacinto Alonso-Azcárate at the University of Castile-La Mancha. This allowed them to determine the exact chemical composition of the six most common classes of C chondrites and provide valuable information about whether raw material extraction will be possible in the future. Trigo-Rodríguez said in a press release from the Spanish National Research Council (CSIC):
The scientific interest in each of these meteorites is that they sample small, undifferentiated asteroids and provide valuable information about the chemical composition and evolutionary history of the bodies from which they come. At ICE-CSIC and IEEC, we specialize in developing experiments to better understand the properties of these asteroids and how the physical processes occurring in space affect their nature and mineralogy. The work now published is the culmination of this team work.
It is crucial to know the material richness of asteroids because they are very heterogeneous. While they are typically classified into three categories: C-type (carbonaceous), M-type (metallic), or S-type (siliceous), asteroids are also classified by spectral properties and orbit. Furthermore, asteroids are essentially material left over from the formation of the solar system and are heavily influenced by their long evolutionary history (approximately 4.5 billion years). Therefore, it is important to know the exact composition of asteroids to determine where various resources (water, ores, etc.) are likely to be located.
*Source: ESO*
According to the team’s findings, mining undifferentiated asteroids (believed to be the precursor to chondritic meteorites) is far from profitable. The study also identified a type of asteroid rich in olivine and spinel ribbons as a potential target for mining operations. The team also noted that water-rich asteroids with high concentrations of water-bearing minerals should be selected. In the meantime, they emphasize the need for additional sample return missions to verify the identity of the precursor bodies before mining can be carried out. Trigo-Rodríguez said:
In addition to the advances that sample return missions represent, there is an urgent need for companies capable of taking decisive steps in the technological development necessary to extract and collect these materials under low-gravity conditions. The processing of these materials and the waste generated would also have significant impacts that should be quantified and appropriately mitigated.
They argue that this will require the development of large-scale collection systems and methods of extracting resources in microgravity. “For certain water-rich carbonaceous asteroids, extracting water for reuse appears to make more sense, either as fuel or as a primary resource for exploring other worlds,” said Trigo-Rodríguez. “This could also provide science with greater insight into certain bodies that could one day threaten our existence. In the long term, we could even mine potentially dangerous asteroids and shrink them so that they are no longer dangerous.” As Grèbol-Tomàs added:
Examining and selecting these types of meteorites in our clean room using other analysis techniques is fascinating, especially due to the diversity of minerals and chemical elements they contain. However, most asteroids contain relatively small amounts of valuable elements, and therefore the aim of our study was to understand the extent to which their extraction would be useful. This sounds like science fiction, but it also seemed like science fiction to me when the first sample return missions were planned thirty years ago.
In any case, the benefits of asteroid mining are immense, which is why the topic has gained so much attention in the last decade. In addition to precious metals, many asteroids are a source of water ice, which could be used to produce fuel for space missions and water for drinking and irrigating crops. This would mean less reliance on resupply missions from Earth and allow robotic and manned missions to achieve greater self-sufficiency. By moving mining and manufacturing to cislunar space and the main asteroid belt, humanity would also reduce the environmental impact of these industries on Earth.
While public enthusiasm for asteroid mining has waned over the past decade, many companies are now researching and developing the necessary technology. Similarly, space agencies such as NASA and JAXA have conducted sample return missions that revealed much about the scientific and material wealth that asteroids may contain. In the near future, China’s Tianwen-2 mission will rendezvous with a NEA and a major asteroid belt comet. Although it may take many decades (or longer) for a space-based resources industry to emerge, there are many willing to jump in from the start.
Further reading: CSIC, MNRAS
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