Ice Geyser (2000)
When the Voyager 2 probe flew past Neptune (top) in August 1989, it also imaged its
largest moon Triton. The pictures showed that although Triton's surface is the
coldest in the known Solar System at -240 Celsius (-400 Fahrenheit), it is still
volcanically active. However, the volcanoes are cryonic — geysers of frigid
nitrogen gas. The Voyager images showed, as does my own rendition here, how the
geysers leave dirty streaks on the landscape as the nitrogen and other materials is
blown across by high altitude winds.
