<Ul> <Li> Mars </Li> </Ul> <Dl> <Dd> Similar solar - heating - driven jets of gaseous carbon dioxide are believed to erupt from the south polar cap of Mars each spring . Although these eruptions have not yet been directly observed, they leave evidence in the form of dark spots and lighter fans atop the dry ice, representing sand and dust carried aloft by the eruptions, and a spider - like pattern of grooves created below the ice by the out - rushing gas . </Dd> </Dl> <Dd> Similar solar - heating - driven jets of gaseous carbon dioxide are believed to erupt from the south polar cap of Mars each spring . Although these eruptions have not yet been directly observed, they leave evidence in the form of dark spots and lighter fans atop the dry ice, representing sand and dust carried aloft by the eruptions, and a spider - like pattern of grooves created below the ice by the out - rushing gas . </Dd> <Ul> <Li> Triton </Li> </Ul>

Where does the heat source need to be for a geyser