Scientists were stunned when the Cassini spacecraft transmitted images of a geyser-like plume spouting from a tiny moon of Saturn no wider than Arizona. Huge geysers seem to be erupting from fissures in Enceladus's south pole, pouring tons of water vapor and ice into a thin ring around Saturn.
To understand this improbable water fountain in space and whether we should expect life to be teeming beneath, we spoke with John Spencer, an expert on the moons of giant planets who is part of the Cassini team, working at the Southwest Research Institute in Boulder, Colorado.
What are the geysers like?JS: They are jets of water vapor and dust—really very fine water ice particles that are coming out of large fractures in the south pole of Enceladus. They were discovered last summer when we flew very close to Enceladus. We actually flew through this plume of water vapor and were able to sample it directly with the Cassini spacecraft.
