There’s another Geochimica Et Cosmochimica Acta, for 15 Feb (vol. 415):
Riches, L. J. Suttle, M. D. Franchi, I. A. et al. Fluid history in the ungrouped C2 Essebi meteorite parent body Pg 146 .2025.12.035
Wilson, B. J. K. Nagashima, K. Barrett, T. J. et al. Aqueous alteration in the C2-ung Tarda meteorite: in situ isotopic evidence from dolomite and magnetite Pg 219 .2025.12.046
Lee, M. R. Griffin, S. Findlay, R. et al. Anhydrous lithic clasts in four CM2 carbonaceous chondrites derived from a thermally metamorphosed planetesimal with CM and CY affinities Pg 235 .2025.12.051
Water: at various times, there has been water (in various forms) throughout the Solar System. After all, hydrogen is the most common element in the entire universe, and oxygen is only a bit further down on the list of common elements. Therefore, the question is not ‘where is the water’ but what forms, and what former traces, of water can we find and comprehend.
Riches et al. start with the C2 (water-rich) carbonaceous chondrite meteorites. Most meteorites in this category are CM chondrites, but some meteorites don’t classify easily. The most notable C-ungrouped meteorite would probably be the Tagish Lake meteorite, but Tarda and Essebi are also oddballs within the C type. Riches and team use the common element- oxygen!- as a tracer.
Straight on to Wilson et al.: water forms aqueous deposits, like carbonates and, well, rust. The presence of the mineral dolomite, and magnetite (an iron oxide) indicate the action of water, and certain actions at that. Water thus links Tarda to Tagish Lake, CM chondrites, CIs, etc.
But some minerals didn’t have water. Meanwhile, asteroids collide all the time, spraying their bits across each others’ surfaces, and into the wider Solar System. It is no news that some meteorites contain stray minerals, originating from another, random asteroid (and the occasional comet). Lee et al. report on the observation of foreign matter in CM chondrite meteorites, and their implications.