Visitors to the largest of Neptune's moons, Triton, will be treated to an array of cryogeysers that are probably composed of nitrogen frost and dark organic compounds. The smoky-looking geysers might be heard from kilometers away as they stream more than 8,000 meters into the thin atmosphere before their tops are whisked away by prevailing winds. Methane and nitrogen ice cover this world whose surface temperature plummets to almost —200 degrees Celsius.

Triton's South Pole