Abstract
We present oxygen isotopic analyses of fragments of the near-Earth Cb-type asteroid Ryugu returned by the Hayabusa2 spacecraft that reinforce the close correspondence between Ryugu and CI chondrites. Small differences between Ryugu samples and CI chondrites in D¢17O can be explained at least in part by contamination of the latter by terrestrial water. The discovery that a randomly sampled C-complex asteroid is composed of CI-chondrite-like rock, combined with thermal models for formation prior to significant decay of the short-lived radioisotope 26Al, suggests that if lithified at the time of alteration, the parent body was small (=50 km radius). If the parent planetesimal was large (>50 km in radius), it was likely composed of high-permeability, poorly lithified sediment rather than consolidated rock.
Original language | English (US) |
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Article number | acea62 |
Journal | Planetary Science Journal |
Volume | 4 |
Issue number | 8 |
DOIs | |
State | Published - Aug 1 2023 |
Keywords
- Carbonaceous chondrites (200)
- Planetary thermal histories (2290)
- Unified Astronomy Thesaurus concepts: Asteroids (72)
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Geophysics
- Earth and Planetary Sciences (miscellaneous)
- Space and Planetary Science