The most likely scenario from the knowledge we have on how other objects form, it probably has a rocky core and a mantle. That mantle is probably some watery, icy mix, with other dirt and constituents. That mantle could be as much as å? of the whole object. Even though it's a small object compared to Earth, there could be a lot of water.  -   Joel Parker     Quotes
The most likely scenario from the knowledge we have on how other objects form, it probably has a rocky core and a mantle. That mantle is probably some watery, icy mix, with other dirt and constituents. That mantle could be as much as å? of the whole object. Even though it's a small object compared to Earth, there could be a lot of water. Joel Parker
 Constituents Dirt Earth