Tritons

Triton is one of Neptune’s moons and is unique because it orbits in the opposite direction to Neptune’s rotation, indicating it was likely captured from the Kuiper Belt—a region of icy objects beyond Neptune. With a cold, icy surface covered in nitrogen frost and geysers spouting nitrogen gas, Triton has a thin atmosphere and a fractured, icy crust. Its retrograde orbit and geological activity suggest a complex history, making it a fascinating example of a captured celestial body with active surface processes, offering insights into our solar system's formation and evolution.