An international team, including a researcher from Lawrence Livermore National Laboratory (LLNL), has determined that one specific particle on the asteroid Ryugu can shed light on the unaltered original materials of its parent body.
In December 2014, the Japanese Aerospace Exploration Agency launched the Hayabusa2 spacecraft to the asteroid 162173 Ryugu. In December 2020, the monster return capsule successfully landed safely back on Earth with pristine pieces of Ryugu it had collected.
Ryugu is an ancient fragment of a larger asteroid that formed very early in the history of the solar system, shortly after the sun’s birth. Samples of this asteroid offer a unique opportunity to determine not only what material the solar system formed, but also how the solar system evolved.
The solar system is formed from a large cloud of swirling gas and dust created by previous generations of stars. This “stardust” is nanometer to micrometer sized particles that are incorporated into planetary bodies, such as Ryugu, as they form.
In the new study, LLNL secondary ion mass spectrometer and cosmochemist Ming-Chang Liu (Division of Nuclear and Chemical Sciences) found that one particle (named C0009) differs mineralogically from other Ryugu particles because it contains a small amount (~0.5 vol%) of anhydrous silicates. Other particles studied so far contain more phyllosilicate and carbonate minerals, suggesting that Ryugu went through an extensive aqueous change on its parent body, similar to the rare mineralogically altered but chemically primitive CI chondrites (a group of rare stony meteorites). The research appears in Natural Astronomy.
Through isotopic analysis of magnesium-rich olivine and pyroxene, the data provides “strong evidence that amoeboid olivine aggregates and magnesium-rich chondrules, two types of high-temperature objects that formed in the solar nebula, made their way into Ryugu’s maternal body,” Liu said. , who serves as the paper’s lead author.
The team analyzed the results of oxygen isotope measurements of Ryugu’s anhydrous silicates, which have strong implications for Ryugu’s origin and by extension the original asteroids of CI chondrite meteorites.
“The oxygen isotope data along with the grain morphology allow us to infer the original materials incorporated into Ryugu’s protolith, as they reveal a possible link between anhydrous silicates in C0009 and other known high-temperature components that are found in non-CI carbonaceous chondrites‘ said Liu.
Ming-Chang Liu et al, Incorporation of 16O-rich anhydrous silicates in the protolith of highly hydrated asteroid Ryugu, Natural Astronomy (2022). DOI: 10.1038/s41550-022-01762-4
Lawrence Livermore National Laboratory
Quote: Team identifies parental body material in Ryugu asteroid (2022, September 23) retrieved September 23, 2022 from https://phys.org/news/2022-09-team-parent-body-materials-ryugu.html
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