The Moon, a disk or a sphere?

In this paper, we present a physical modeling activity whose objective is to allow students determine the differences between disk and sphere using pure scientific criteria. Thereunto, reproduce Sun-Earth-Moon system with low-cost materials compare illumination effects on Moon considering two possible shapes for it (a disk). The analysis based shape of Terminator line produced in each case as function angle. results obtained are first discussed then applied so that one can interpret observed patterns other celestial bodies, such Venus or even Earth. Thereby, be very useful unmask unscientific idea Flat entire easily replicable may promote more realistic view science its methods.