Assessing the metal and rare earth element mining potential of undifferentiated asteroids through the study of carbonaceous chondrites

TL;DR

This study argues that undifferentiated, carbonaceous asteroids bear substantial potential for resource extraction beyond metal-rich differentiated bodies. By applying ICP-MS and ICP-AES to a representative suite of carbonaceous chondrites, it quantifies bulk abundances of transition metals and rare earth elements, revealing group-specific enrichment patterns and a notable correlation between REE content and petrologic type. CK and CV chondrites emerge as REE-rich, while CO chondrites appear particularly pristine for native metal preservation; aqueous alteration generally reduces REE content. The findings guide target selection for space mining and sample-return missions, emphasizing pristine K-class asteroids linked to CO/CV signatures and the need for in-situ verification of parent bodies, all within a framework that also considers robotics, ISRU, and international governance.

Abstract

Undifferentiated asteroids, particularly the parent bodies of carbon-rich chondrite groups, might be promising candidates for future space resource utilization due to their primitive composition and potential to host valuable metals and rare earth elements. However, our understanding of their bulk elemental composition remains limited, as most data are derived from reflectance spectra with low mineralogical resolution. Sample return missions have started to change that, as returned materials are already available to study. Still the available meteorites provide a valuable source of information about the diversity of undifferentiated asteroids in the interplanetary space. To improve compositional insights, we conducted Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and ICP-AES (Inductively coupled Plasma Atomic Emission Spectroscopy) analyses on a representative suite of carbonaceous chondrites. These meteorites, considered analogs of undifferentiated asteroids, preserve materials from the early solar system and provide a geochemical record of their parent bodies. Our results highlight the abundance and distribution of transition metals, siderophile elements, and rare earth elements across several chondrite groups. These findings support the view that C-type asteroids may serve as viable sources of critical materials, while also informing future mission planning, extraction strategies, and the development of new technologies for low-gravity resource operations.

Figures (8)

• Figure 1: Bulk elemental composition of analyzed CC specimens. Vertical dashed lines mark the atomic number of relevant atomic species. In the CI panel we compared our Orgueil measurements with those of CI chondrites 2019nuco.conf..165L.
• Figure 2: Measured chemical abundances of valuable metals in the selected CC specimens.
• Figure 3: Mean chemical abundances of third-row transition elements in the selected CC specimens. The mean values for each group take their source from the data in Figure \ref{['fig: metal abundances']}. The elemental abundances are shown relative to the CI values reported in 2019nuco.conf..165L.
• Figure 4: Mean chemical abundances of the third-period transition elements in the analyzed charbonaceous chondrites compared to other bodies in the Solar System. All abundances have been normalized to the reported CI values in 2019nuco.conf..165L. Bluish markers (circles, squares and triangles) show the relative abundance of transition elements in iron meteorites: 2005GeCoA..69.4733C2014Chernonozhkin_iron2014DuanRegelous_iron, respectively. In 2005GeCoA..69.4733C several iron meteorites abundances are reported. In this figure we arbitrarily show that of the Cape of Good Hope IVB iron meteorite to ease the interpretation, as all iron meteorites from the work show similar abundances. The upper Earth crust elemental abundances from 2003TrGeo...3....1R are shown as browny circles with meridian lines. Pink diamonds show the relative elemental abundance in Earths most proliferant mineral deposits: Bushveld complex (South Africa) for Cr 2015Cawthorn_Bushveld, Tenke Fungurume mines (D. R. Congo) for Co and Cu 2012Fay_TenkeFungurume2014LundinMiningCorp_TenkeFungurume, Ranglan deposit (Canada) for Ni 2004Seabrook_Raglan and the Red Dog mine (Alaska, USA) for Zn 2002Jennings_RedDog2004Kelley_RedDog. Crescent grey moons show the relative abundance values from the PCA 02007 lunar meteorite 2010MPS...45..917J. In 2010MPS...45..917J the analysis of other breccias are shown, but they all show similar elemental compositions. As in the case of iron meteorites, we only show the abundance of one of them to ease the graph interpretation.
• Figure 5: Measured chemical abundances of REEs in the analyzed CC specimens. Elemental abundances are normalized by the corresponding abundances in CI 2019nuco.conf..165L.