Related Experiment Video
Updated: Aug 6, 2026
06:04
Simulation of the Planetary Interior Differentiation Processes in the Laboratory
Published on: November 15, 2013
Refractory inclusions in Bennu samples indicative of outer Solar System accretion
Noriyuki Kawasaki1, Toru Matsumoto2,3, Sota Arakawa4
1Department of Earth and Planetary Sciences, Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan. kawasaki@eis.hokudai.ac.jp.
Nature Communications
|July 18, 2026
Summary
NASA
Area of Science:
- Cosmic Dust and Planetary Science
- Early Solar System Evolution
- Asteroid Sample Analysis
Background:
- NASA's OSIRIS-REx mission returned samples from asteroid Bennu.
- Bennu's material includes aqueous alteration products and rare high-temperature components.
- Understanding these components provides insights into early Solar System processes.
Purpose of the Study:
- To characterize refractory inclusions in Bennu samples.
- To determine their formation conditions and chronological history.
- To compare Bennu's inclusions with those from other celestial bodies.
Main Methods:
- Integrated petrographic analysis of Bennu samples.
- Oxygen-isotopic characterization of inclusions.
- 26Al-26Mg chronological analysis.
Main Results:
- Identified small refractory inclusions (<~100 µm) in Bennu samples.
- These inclusions show evidence of in situ aqueous alteration.
- Their isotopic and chronological data indicate early Solar System formation and affinity with Ryugu and chondritic meteorites.
- Large refractory inclusions are absent in analyzed Bennu samples.
Conclusions:
- Bennu's refractory inclusions formed early in Solar System history.
- Their characteristics suggest widespread transport and mixing of inner-disk solids.
- The absence of large inclusions implies accretion beyond the Jupiter pressure bump, filtering dust populations.
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