Ryugu’s nucleosynthetic heritage from the outskirts of the Solar SystemOPEN ACCESS
Timo Hopp, Nicolas Dauphas, Yoshinari Abe, Jérôme Aléon, Conel M. O’D. Alexander, Sachiko Amari, Yuri Amelin, Ken-ichi Bajo, Martin Bizzarro […] Hisayoshi Yurimoto
Science Advances
20 Oct 2022
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“Little is known about the origin of the spectral diversity of asteroids and what it says about conditions in the protoplanetary disk. Here we show that samples returned from Cb-type asteroid Ryugu have Fe isotopic anomalies indistinguishable from Ivuna-type (CI) chondrites, which are distinct from all other carbonaceous chondrites. Iron isotopes, therefore, demonstrate that Ryugu and CI chondrites formed in a reservoir that was different from the source regions of other carbonaceous asteroids. Growth and migration of the giant planets destabilized nearby planetesimals and ejected some inwards to be implanted into the Main Belt. In this framework, most carbonaceous chondrites may have originated from regions around the birthplaces of Jupiter and Saturn, while the distinct isotopic composition of CI chondrites and Ryugu may reflect their formation further away in the disk, owing their presence in the inner Solar System to excitation by Uranus and Neptune.”
