Icy Moons
Cryovolcano
A cryovolcano is a volcano that erupts volatile substances such as water, ammonia, methane, and brines instead of molten silicate rock. Cryovolcanism shapes the geology of many outer Solar System bodies, with confirmed activity on Enceladus and Triton and strong evidence on Europa, Ceres, and Pluto.
Triton (moon)
Triton is the largest moon of Neptune and the only large satellite in the Solar System with a retrograde orbit, indicating capture rather than in‑situ formation. Discovered on October 10, 1846 by William Lassell, Triton is an icy world with a thin nitrogen atmosphere, active geysers observed by Voyager 2 in 1989, and surface terrains suggesting ongoing cryovolcanic and tectonic processes.