Only recently have space missions begun to solve this beguiling Solar System mystery--that a small number of distant moons have been successfully hiding, from the curious eyes of astronomers, life-sustaining liquid water beneath secretive shells of ice.
The scientists also ruled out the possibility that the mysterious features actually exist on Titan's surface in the form of frozen methane rain or icy lava erupted from cryovolcanoes. Such surface features would show a different chemical signature and would be visible for much longer periods of time than the bright features observed in this study. The bright features were visible from time spans of only 11 hours to five weeks.
Several possibilities could provide an answer as to why the moon would have charcoal-black surface patches, even though it is circling a dwarf planet that is as bright as freshly fallen snow. One theory that has been suggested proposes that, unlike larger objects such as Makemake, its own little companion moon is so small that it cannot gravitationally keep a grip onto a bright and icy crust, which then sublimates, undergoing a sea-change from solid to gas under the melting influence of warming sunlight. This would make the little moon akin to comets and other KBOs, many of which are well-coated with very dark material.