Active sites in heterogeneous ice nucleation—the example of K-rich feldspars

From dust to ice How does ice form on the surfaces of aerosol particles? The process is important for climate and atmospheric properties but poorly understood at the molecular level, in part because the nature of the sites where ice growth begins is unclear. Kiselev et al. used electron microscopy and computer simulations to study the deposition of aligned ice crystals on feldspar, a major component of mineral dust (see the Perspective by Murray). Surface defects of the feldspar were responsible for its high ice-nucleation efficiency. Science , this issue p. 367 ; see also p. 346