Extended Data Fig. 5: Bulk C and N abundances and isotopic compositions of Bennu sample (OREX-803058-0).
From: The variety and origin of materials accreted by Bennu’s parent asteroid
Stepped combustion profiles from Bennu sample OREX-803058-0 (Methods) for (a) carbon and (b) nitrogen. Abundances are plotted as the red histogram, scaled on the left axis; isotopic compositions are plotted as blue dots, scaled on the right axis. The colored bars indicate the peak combustion temperature for nanodiamonds (blue)135, and likely graphite (green) and silicon carbide (yellow), although the release temperature is likely broader, primarily as a function of crystallinity and grain size136. The C isotopic compositions of approximately –10 ‰ and +70 ‰ indicate volatile organics and carbonates, respectively. For N, volatile organics coincide with δ15N ~ + 20 ‰ and less volatile organics from ~+40 to +100 ‰. Error bars represent 2 SD and are smaller than the symbol where not visible.
