Fig. 4: Isotopic mapping to identify presolar grains in Bennu samples (OREX-501018-100, OREX-501049-0 and OREX-501080-0) and comparison of their abundances with other carbonaceous astromaterials.
From: The variety and origin of materials accreted by Bennu’s parent asteroid
a, NanoSIMS δ17O/16O ratio image of a region containing an isotopically anomalous O-rich presolar grain. Scale bar, 2 µm. b, NanoSIMS δ13C/12C ratio image of a region containing a presolar SiC grain that is denoted by the arrow. c, Abundances of presolar SiC, O-rich grains and graphite in Bennu (this study) compared with Ryugu, CI and CM chondrites (see Methods for sources of non-Bennu data). The presolar O-rich abundance for CI chondrites is an upper limit. Error bars are 1 s.d. around mean values.
