The Tarda Meteorite: A Window into the Formation of D-type Asteroids
Type | Article | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Date | 2021-05 | ||||||||||||
Language | English | ||||||||||||
Author(s) | Marrocchi Yves1, Avice Guillaume2, Barrat Jean-Alix3 | ||||||||||||
Affiliation(s) | 1 : Université de Lorraine, CNRS, CRPG, UMR 7358, Vandœuvre-lès-Nancy, F-54501, France 2 : Université de Paris, Institut de physique du globe de Paris, CNRS, F-75005 Paris, France 3 : Université de Brest, CNRS, IRD, Ifremer, LEMAR, F-29280 Plouzané, France |
||||||||||||
Source | Astrophysical Journal Letters (2041-8205) (American Astronomical Society), 2021-05 , Vol. 913 , N. 1 , P. L9 (8p.) | ||||||||||||
DOI | 10.3847/2041-8213/abfaa3 | ||||||||||||
WOS© Times Cited | 29 | ||||||||||||
Abstract | Dynamic models of solar system evolution suggest that D-type asteroids formed beyond Saturn's orbit and represent invaluable witnesses of the prevailing conditions in the outer solar system. Here, we report a comprehensive petrographic and isotopic characterization of the carbonaceous chondrite Tarda, a recent fall recovered in the Moroccan Sahara. We show that Tarda shares strong similarities with the D-type-derived chondrite Tagish Lake, implying that Tarda represents a rare sample of D-type asteroids. Both Tarda and Tagish Lake are characterized by the presence of rare 16O-rich chondrules and chondrule fragments, high C/H ratios, and enrichments in deuterium, 15N, and 13C. By combining our results with literature data on carbonaceous chondrites related to C-type asteroids, we show that the outer solar system 4.56 Gy ago was characterized by large-scale oxygen isotopic homogeneities in (i) the water–ice grains accreted by asteroids and (ii) the gas controlling the formation of FeO-poor chondrules. Conversely, the zone in which D-type asteroids accreted was significantly enriched in deuterium relative to the formation regions of C-type asteroids, features likely inherited from unprocessed, D-rich, molecular-cloud materials. |
||||||||||||
Full Text |
|