This model was rendered using MATLAB R2016a on the ICQ model of the PSI made by Philip Stooke from the data of the Galileo and Voyager missions. The original model has a very low resolution, so the model was very "poly" look. To avoid this I interpolate into much more points than the original. It's scaled to 1 in 4 x 106 or one in four million and 1 in 2 x 106 or one in two million.
The file's names explained: name_1_x_10_y.stl is 1 : x * 10y. So _1_6_10_7 is 1:600000000 or one in 60 million.
Amalthea is the biggest moon of Jupiter that it's not one of the Galilean Moon (Io, Europa, Ganymede and Callisto). Its shape is very irregular, because it is a rubble pile. In astronomy, rubble piles are objects formed by the acreation of many smaller objects, but without the melting required for making the object spherical.
Orbital period: 11 h, 57 min, 23 s.
Composition: Icy body, rubble pile.
Density: 0.857 g/cm3.
Dimensions: 250 km × 146 km × 128 km.
Model scale: 1:4x106 (6cm) 1:2x106 (12cm)