Nitrogen isotopic compositions of NC and CC meteorites and comets. The bottom row concerns iron meteorites, the middle row chondrites and the upper row comets, so that the vertical axis can be grossly interpreted as a temporal sequence, from bottom to top. Although both NC and CC meteorites are ¹⁵N-rich relative to nebular gas, the former are closer to the solar value estimated from the Genesis samples (Marty et al. 2011). Modified from Grewal et al. (2021).