Enceladus is only 310 miles in diameter, but despite its petite size, it’s one of the most scientifically compelling bodies in our solar system. Enceladus is the sixth-largest moon of Saturn and is mostly covered by ice, reflecting almost all the sunlight that strikes it.
In 2005, NASA’s Cassini spacecraft discovered water vapor geysers. The geysers spew icy water particles and gases. Several gases, including water vapor, carbon dioxide, methane, perhaps a little ammonia and either carbon monoxide or nitrogen gas make up the gaseous envelope of the plume.
This view of Enceladus looks toward the leading hemisphere of Enceladus. The image was taken by the Cassini spacecraft on Sept. 8, 2015 at a distance of approximately 80,000 miles (129,000 kilometers) from the moon.