This is an image of Triton.
Image from: NASA
Triton Interior
The diagram to the left shows a cutaway of the possible interior structure of Triton. The composition of Triton is mostly ice, therefore there is probably a small core of some rocky material buried inside, overlain with mantles of ice of various phases. One of the phases of ice is water however, and if water is present it could provide and environment suitable forlife.
If the interior is warm enough, there may be enough energy for interior convection, or the turning over of layers inside Triton. This type of interior motion leaves clues on the surface of a planet, such as folds and deep crevaces. Surface plate tectonics is a big clue about interior motions of the Earth.
The fact that this moon is made primarily of ice suggests a certain path for it's evolution.
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