Spacecraft to sample water plumes from Saturn moon

On Wednesday, Cassini will storm through a jet of water vapor and frozen particles erupting from the south pole of Enceladus, one of Saturn’s many moons.

This isn’t the spacecraft’s final flyby of Enceladus, but it is the deepest dive through the plume, giving researchers an unprecedented taste of its contents and more clues about how friendly this little moon would be to microbial life.

“Enceladus is not just an ocean world – it’s a world that might provide a habitable environment for life as we know it”, said Curt Niebur, a Cassini program scientist, in a statement on Monday.

In spite of that, however; Cassini researchers will still get quite a bit of valuable data from the sampling mission, and it could have implications for our understanding of the existence of alien life. The porous nature of the core means that it would probably lose heat rapidly and this suggests that a recent “incidental heating” event may be responsible, they report.

Cassini will sample water ejecting up from geysers spraying up from the Saturn’s moon on Wednesday, October 28.

Scientists hope that the trip will tell them how much icy material is emanating from Enceladus, and perhaps what kinds of complex organic molecules it contains, though not with enough detail to determine if anything is alive.

Based on lab experiments, Enceladus’ hydrogen “could provide energy for possible life forms beneath the surface”. The critical measurement for these questions is the detection of molecular hydrogen by the spacecraft.

A cross-section of Enceladus and its plumes.

During the flyby, Cassini will also be snapping images of Enceladus’ surface aglow in light reflected from Saturn.

Cassini launched in 1997 and entered orbit around Saturn in 2004.

– The flyby will help solve the mystery of whether the plume is composed of column-like, individual jets, or sinuous, icy curtain eruptions – or a combination of both. “It’s not our last, but arguably this one is going to be our most dramatic”, said project manager Earl Maize.

Saturn, a gaseous planet and the second-largest in the solar system, is about nine time the size of Earth and is the sixth farthest from the Sunday.

Cassini will fly within 40 kilometres of the surface, and straight through the moons mysterious plumes – which are fuelled by a subsurface ocean that could potentially harbour life.