Discovery of the Evolving Process of Planetary Embryos of Terrestrial Planets Early in the Solar System

May 27(Sat), 2017

Associate Professor Ryoji Tanaka and Professor Eizo Nakamura of the Institute for Planetary Materials at Okayama University have separated a spherical particle called a chondrule from an enstatite chondrite, a kind of primordial meteorite that is considered to be a fragment of an astronomical body formed early in the formation period of the Solar System, and have succeeded in conducting a high precision oxygen isotope ratio analysis of the chondrule. They have shown that the oxygen isotopic compositions of terrestrial planets and protoplanets that underwent differentiation processes were determined by a reaction between olivine-rich chondrule and silicon monoxide (SiO)-rich gas. This reaction occurred within a few million years of the birth of the Solar System, as the inner solar protoplanetary disk changed to a reductive environment. Their research results will be published online in the British scientific journal “Nature Astronomy” at 4 pm on May 26th (midnight on the 27th in Japan).

These research results not only make the oxidation-reduction status of the inner solar protoplanetary disk clear in a material scientific way, but also offer important knowledge in understanding the chemical compositions of terrestrial planets as well as planet interior chemical compositions.


Article Information

DOI: 10.1038/s41550-017-0137

Journal: Nature Astronomy

Title: Silicate–SiO reaction in a protoplanetary disk recorded by oxygen isotopes in chondrules

Authors: Ryoji Tanaka & Eizo Nakamura

Year of Publication: 2017                                                                                                                                                    

Article number: 0137                                                                                      


Okayama University Silicon Valley Office (OUSVO)

Contact:   Mototaka Senda, Ph.D.

Phone:      (1)510-894-3067



Solar System, chondrule, solar protoplanetary

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