NASA releases new global maps of Earth at night

Enceladus's south pole has odd, warm fractures, and plumes of liquid water coming from an internal ocean many believed was impossible in such a small, cold world. Now that we know Enceladus has all the necessary ingredients for this to happen, we are lacking only the proof of life itself. In extreme environments on Earth, hydrogen can play that role. But everything else is there: water, organics, an energy source and more. "This completes that story". However, new evidence showed that the plumes could be coming from subsurface water pockets.

In a subsequent trip through the plume, Cassini's INMS was put into a mode that minimized analytical artifacts that had compromised the measurements of the energy source molecular hydrogen, or H2, during previous flybys.

As we suggested in our article preceding this announcement, the inclusion of Hunter Waite, the leader of the Cassini Ion and Neutral Mass Spectrometer team at the Southwest Research Institute in Texas, was notable. Do they exist? We can't be sure just yet.

And the only plausible source, they concluded, are hydrothermal reactions between hot rocks and the water in the moon's ocean.

Enceladus is a long way from Earth. "This is like candy for microbes".

Showing Enceladus is habitable is one thing, finding life is quite another. This means there's plenty of geological activity, increasing the chances for life. The conditions for life to arise may not be as limiting as we once thought. The inferred temperature is high enough that the process might create large-scale convective motion (think "pot of boiling oatmeal"), Sekine, Hsiang-Wen Hsu (University of Colorado, Boulder) and others speculated in their silica analysis.

"The message is in the molecules", says Christopher Glein, another member of Waite's group at SwRI.

'Nasa bases this determination on the amount of hydrogen in plumes emanating from the moon's south pole, ' he added. Cowing's hunches. So it's time that we better wait for the moment! Cassini is running low on fuel, and if it were to crash into Enceladus it might destroy any extraterrestrial ecosystem living there. Scientists have found food on that moon that they say could sustain potential life. The spacecraft will crash into Saturn on 15 September.

The discovery, to be published today in the journal Science and announced in a NASA press conference, relates to the ocean of liquid water that lies under 30 kilometres of ice on Enceladus, which at 500 km wide is among the larger of the ringed gas giant's dozens of moons.

  • Carolyn Briggs