Dust grains older than our Sun found in asteroid Ryugu samples

Washington, DC— Microscopic grains of historic materials that predate our Sun’s start had been present in samples returned from the asteroid Ryugu by the Hayabusa2 mission, based on new work from a world staff led by Carnegie’s Jens Barosch and Larry Nittler and revealed in The Astrophysical Journal Letters.  

Named after a Japanese folktale, Ryugu is a near-Earth object formed sort of like a spinning high that orbits the Sun each 16 months. Hayabusa2 was the primary mission to convey materials again to Earth from a primitive asteroid, providing distinctive perception into the chemical make-up of the constructing blocks from which our Solar System was fashioned.

“Different types of presolar grains originated from different types of stars and stellar processes, which we can identify from their isotopic signatures,” Barosch defined. Isotopes are variations of parts with the identical variety of protons, however a unique variety of neutrons.

He added: “The opportunity to identify and study these grains in the lab can help us understand the astrophysical phenomena that shaped our Solar System, as well as other cosmic objects.”

Each era of stars seeds the uncooked materials from which the following era is born. Like a phoenix rising from the ashes, our Sun originated greater than 4.5 billion years in the past when a supernova explosion spewed materials right into a preexisting cloud of fuel and dirt, inflicting it to break down in on itself. The remnants of this course of fashioned a rotating disk of fabric across the child Sun from which the planets and different objects coalesced—together with the mum or dad our bodies that finally crashed into one another and broke aside to turn into asteroids and meteorites.

The Hayabusa2 samples enable scientists to probe Ryugu’s make-up with refined microanalytical devices and evaluate it to materials present in primitive meteorites referred to as carbonaceous chondrites which have crashed to Earth.

The staff detected all of the beforehand identified sorts of presolar grains—together with one shock, a silicate that’s simply destroyed by chemical processing that’s anticipated to have occurred on the asteroid’s mum or dad physique. It was present in a less-chemically-altered fragment that possible shielded it from such exercise.

“The compositions and abundances of the presolar grains we found in the Ryugu samples are similar to what we’ve previously found in carbonaceous chondrites,” defined Nittler, who undertook this work at Carnegie, however just lately moved to Arizona State University. “This gives us a more complete picture of our Solar System’s formative processes that can inform models and future experiments on Hayabusa2 samples, as well as other meteorites.”

Other Carnegie co-authors embrace Jianhua Wang, Conel Alexander, Richard Carlson, and George Cody.


This work was carried out beneath the auspices of the Hayabusa2 Initial Analysis Team, particularly the Chemistry sub-team led by Prof. H. Yurimoto and the Macromolecule sub-team led by Prof. H. Yabuta. This work was funded partly by NASA.

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