The interior composition can be guessed from density mass of these moons, and so determined the densities to be about 1.2 (refer to the reference information for exact measurements of the icy moons). This density which is closer to that of ice than rock, so most of these moons must be made of ice. The fact that they are made primarily of ice suggests a certain path for their evolution. |
The Voyager spacecraft could not measure the interior of the moons, however. Instead they measured the density. The density of iron or rock is between 3 and 5. The density of ice is 1. Voyager measured the densities to be about 1.2 (refer to the reference information for exact measurements of the icy moons), which is closer to that of ice than rock, so most of these moons must be made out of ice. The fact that they are made primarily of ice suggests a certain path for their evolution. |
Scientists can only guess what the inside is made of, but when the Voyager missions flew by some the icy moons, measurements were made that showed that the inside of the moons might also made of ice. The fact that the major moons are made primarily of ice suggests a certain path for the evolution of these bodies. |
