Rapidly evolving composition of nebular infall recorded by magnesium isotopes in refractory inclusions.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 42461769.
- Also identified by DOI 10.1073/pnas.2529765123.
- No licence information is recorded for this record.
- Because redistribution is not established, this page shows the abstract only. Follow the links below for the full text.
Abstract
The <sup>26</sup>Al-<sup>26</sup>Mg systematics in calcium-aluminum-rich inclusions (CAIs)-the oldest known Solar System solids-has traditionally been used to provide high-resolution temporal constraints on the early Solar System evolution. More recently, the study of variations in the initial Mg isotope composition has emerged as a means to probe for potential compositional heterogeneity in the nascent solar nebula. Here, we report high-precision magnesium isotope data for a collection of 19 CAIs that captures the diversity of refractory inclusions. The data reveal widespread Mg isotope heterogeneity prior to <sup>26</sup>Al decay, covering a large range from -0.285 to +0.088‰. Combined with literature data, the distribution of Mg isotope heterogeneity in CAIs forms a continuum and no longer defines distinct populations. Our findings therefore suggest a continuous CAI formation process that captured a rapid temporal change in the composition of infalling material from the parental molecular cloud of the Solar System.