Ring particle bolometric Bond albedo Saturn bolometric Bond albedo =0.342 B Earth elevation above the ring plane B' Solar elevation above the ring plane Specific heat ( ) C(B', ) Particle fractional lit area C(B, ) Particle fractional visible area Sun-Saturn distance in astronomical units Infrared emissivity of ring particles, F1 Direct sunlight F2 Sunlight reflected by Saturn F3 Thermal radiation from Saturn F4 Sunlight scattered by nearby particles Thermal inertia ( ) K Thermal conductivity ( ) sin(B) Solid angle of the lit planet hemisphere Solid angle of the planet hemisphere Solid angle subtended by all nearby particles p Porosity of the particle regolith z Depth in particle Volume density of the regolith ( ) Solar constant =1370 , Stefan constant Ring optical depth Ring brightness temperature Particle surface temperature Saturn planet effective temperature,  K Particle mean motion