¹Megan Broussardet al. (>10)
Meteoritics & Planetary Science (in Press) Open Access Link to Article [doi: 10.1111/maps.701381]
¹Department of Earth, Environmental, and Planetary Sciences and the McDonnell Center for the Space Sciences,Washington University in St. Louis, St. Louis, Missouri, USA
Published by arrangement with John Wiley & Sons

CI chondrites are a compositionally primitive group of meteorites that haveundergone extensive aqueous alteration, providing insights into the evolution of primitiveplanetesimals. Oued Chebeika 002 is the most pristine CI chondrite to date. In this work,we report its mineralogy, bulk chemistry, oxygen and potassium isotope ratios, andcosmogenic radionuclides 10 Be, 26 Al, and 36 Cl. The 10 Be cosmic ray exposure ages of OuedChebeika 002 samples are 2.6 0.5 and 2.9 0.7 Myr. The d41 K of two samples is0.114 0.019 and 0.247 0.044 &. We find that the mineralogy, oxygen isotopes,potassium isotopes, and bulk chemistry of Oued Chebeika 002 overlap with those ofsamples returned from the asteroids Ryugu and Bennu. We therefore propose that CI chondrites and the asteroids Bennu and Ryugu may have originated from a common parentbody, for which we propose the name “Naunet,” after an Egyptian goddess of primordialwater. Naunet formed in the outer solar system and underwent aqueous alteration. In themain belt, Naunet broke up, producing rubble-pile asteroids, including Bennu, Ryugu, andthe secondary CI chondrite parent body/bodies, fragments of which survived passage to theEarth’s surface, becoming CI chondrites.