 Amalthea is irregularly shaped , with the best ellipsoidal approximation being 250 × 146 × 128 km . From this , Amalthea 's surface area is likely between 88 @,@ 000 and 170 @,@ 000 square kilometers , or somewhere near 130 @,@ 000 . Like all other inner moons of Jupiter it is tidally locked with the planet , the long axis pointing towards Jupiter at all times . Its surface is heavily scarred by craters , some of which are extremely large relative to the size of the moon : Pan , the largest crater , measures 100 km across and is at least 8 km deep . Another crater , Gaea , measures 80 km across and is likely twice as deep as Pan . Amalthea has several prominent bright spots , two of which are named . They are <unk> Facula and Ida Facula , with width reaching up to 25 km . They are located on the edge of ridges . 
