Geology of Triton

The geology of Triton encompasses the physical characteristics of the surface, internal structure, and geological history of Neptune's largest moon Triton. With a mean density of 2.061 g/cm³,^[1] Triton is roughly 15-35% water ice by mass; Triton is a differentiated body, with an icy solid crust atop a probable subsurface ocean and a rocky core. As a result, Triton's surface geology is largely driven by the dynamics of water ice and other volatiles such as nitrogen and methane. Triton's geology is vigorous, and has been and continues to be influenced by its unusual history of capture, high internal heat, and its thin but significant atmosphere.

Nearly nothing was known of Triton's geology until the Voyager 2 spacecraft flew by the Neptune system in 1989, marking the first and only up-close observations of the moon as of 2024. A number of proposals have been made to follow up on Voyager 2's discoveries, such as Trident and Triton Hopper.^[2][3]