Distance of the circumplanetary H₂O ice lines as a function of planetary mass. A distance of 5.2 AU to a Sun-like star is assumed. The shaded area indicates the 1σ scatter of our simulations based on the posterior distribution of the disk Planck mean opacity (κ_P) and the shutdown accretion rate for moon formation (Ṁ_shut). The labeled circles at 1 M_Jup denote the orbital positions of Jupiter’s moons Io, Europa, Ganymede, and Callisto. Orange indicates rocky composition, blue represents H₂O-rich composition. Circle sizes scale with the moons’ radii. a) Disk reflectivity (k_s) is set to 0.2. b) Same model parameterization but now with disk reflectivity k_s = 0.4.