Saturn's icy moon Enceladus sprays material into space from its south pole. What is coming out?

The answer

Cassini flew through jets from Enceladus's "tiger stripe" fractures and sampled water, salts, organics, and silica grains that point to a global ocean with hydrothermal vents. The moon is literally venting its ocean into Saturn's E ring.

Correct answer: Water vapor and ice from a subsurface ocean