Exponential correlation between the meteorite H content (Appendix A) and its ESPAT parameter (left) and NOPL parameter (right), including different types of hydrated CC meteorites as well as Ryugu. Parameter errors for the meteorites are smaller than the symbols. The thick black line is the exponential regression of the meteorite data; the two dashed black lines define the prediction bounds, which indicate the area in which a new data point would fall with a 95% probability. The mean H content values for Ryugu, determined using the meteorite exponential correlations, are 0.52 wt.% in both cases. Ryugu H content relative variation (horizontal bars; 0.313 wt.%–0.675 wt.% using ESPAT and 0.415 wt.%–0.643 wt.% using NOPL) is computed using the minimum and maximum values of the ESPAT and NOPL spectral parameters (vertical bars), respectively.