 Amalthea is in a close orbit around Jupiter and is within the outer edge of the Amalthea Gossamer Ring , which is formed from dust ejected from its surface . From its surface , Jupiter would appear 46 @.@ 5 degrees in diameter . Amalthea is the largest of the inner satellites of Jupiter . Irregularly shaped and reddish in color , it is thought to consist of porous water ice with unknown amounts of other materials . Its surface features include large craters and ridges . 
