Potential transformation trends of asteroidal spectral types driven by SW: (a) transformation trends of asteroidal spectral types on the S-complex. Unirradiated H6 and LL5/6 ordinary chondrites (large solid symbols) are the best match for Q-types, while after irradiation, they tend to move toward Sq- and S-types, indicating an evolution trend of “Q-Sq-S” driven by SW. The line α was definedin DeMeo et al. (2009) and used to separate S-complex from other types. The vertical axis PC1’ (first principal component) and horizontal axis PC2’ (second principal component) are also calculated based on DeMeo et al. (2009). For background on our choice to use PC1’ and PC2’ here, we refer to Appendix C. All of the near-Earth objects (NEOs) data come from Binzel et al. (2019); (b) Transformation trends of asteroidal spectral types on carbonaceous composition. The unheated and unirradiated Murchison are close to the Ch and Cgh-type area, and as heated temperature and irradiated energy increases, they generally move toward the B-type and ultimately fall into the B-type range, revealing that a Ch or Cgh-type could become a B-type due to SW. The vertical axis Slope_0.85−1.8 is the linear fitting slope within 0.85–1.8 μm region, and the values of horizontal axis PC4’ (fourth principal component) are calculated on the basis of DeMeo et al. (2009). For the reason we use Slope_0.85−1.8 and PC4’ here, please see Appendix C. For data on the asteroids used here, we refer to Table D.1.