The definition of a finger is a digit on your hand or anything that looks like or functions like a finger. Thumb - The thumb is the short, stubby finger that can rotate in all directions (opposable thumb). The anatomical name for the thumb is the 1st finger.
Pluto is thought to be made of mostly ice. It probably also has a small rocky core which might contain some metals. The ice on the surface of Pluto is made of frozen nitrogen, methane and carbon monoxide. The ice covering Pluto reflects a lot of sunlight making it appear brighter than it would if it had been covered with a darker rocky material. 1  Javascript must be enabled to use Cool Cosmos.
Surface of Pluto. Lying 30 to 50 times as far from the sun as Earth, Pluto's composition bears a greater resemblance to the rocky terrestrial planets than the gas giants that are its neighbors. The surface of the dwarf planet appears to be dominated by ices, with some rock mixed in.cientists can use Pluto's largest moon, Charon, which is close to the size of the dwarf planet and similar in composition, to study the surface of Pluto.