One paper to report in Earth and Planetary Science Letters for 15 August (vol. 664):
Shollenberger, Q. R. Render, J. Wimpenny, J. et al. Elemental and isotopic signatures of Asteroid Ryugu support three early Solar System reservoirs Art. 119443 .2025.119443
Isotopes are different from each other… but not by much. One or two neutrons’ difference makes isotopes heavier or lighter, but except for deuterium, the marginal gain or loss is marginal indeed. Hence, it takes serious processing to sort most isotopes, one way or the other. Conversely, spotting an enrichment or deficiency of these neutrons indicates something serious happened.
The early Solar System was a serious place indeed, and small bodies (asteroids and, to some extent comets) record what happened there and then. According to Shollenberger et al., “then” was the formative years for the early solids of the (outer) Solar System, and “there” was the formation location of Ryugu- the distinct formation location. It’s clear that outer Solar System materials are not the same as inner Solar System stuff, by multiple arguments: multiple elements and isotopes, used as tracers. Shollenberger et al. argue, with hi-res studies of the Ryugu sample from Hayabusa2, they can distinguish the Ryugu location from the rest of the outer Solar System.