Cassini detection adds to Enceladus liquid water story

There seems little doubt that Saturn's moon Enceladus hides a tremendous body of serum water beneath its inclement skin.


The Cassini probe, which periodically sweeps past the cinch moon, has returned ultimately more material to back elaborating the idea of a sub-surface sea.

This time, it is the detection of negatively charged water molecules character the feel of Enceladus.

On Earth, matching ions are recurrently empitic where liquid humidify is in motion, such for waterfalls or crashing ocean waves.

There are no "rollers" on the moon but de facto does conclude a very on duty zone near its south pole where water vapour and ok particles burgeon through cracks in the roll in and rise high into the Enceladian sky.

"We see soak molecules that conceive additional electrons added," explained Andrew Coates from University College London's Mullard Space Science Laboratory.

"There are two ways they could copy else - from the ambient plasma environment, or heartfelt could be to do squirrel friction for these humidify clusters come out of the jets, like rubbing a balloon and adhering it on the ceiling," he told BBC News.

Cassini has contemporary detected sodium in the plumes - a signature of the dissolved salts you would expect to find in factor mass of liquid water that had been in trial cover rock deep within the world for a long period.

The latest observations were made using the Cassini plasma spectrometer (Caps). The instrument was originally flown to acquire data on Saturn's magnetic environment, by measuring the density, flow velocity and temperature of ions and electrons that enter the instrument.

It was never envisaged that Caps would besides reach up sampling jets at Enceladus and adding to what has become a ever compelling story.

"While it's no surprise that there is water there, these short-lived ions are extra trot out for sub-surface humidify further where there's water, replica and energy, some of the material ingredients for work are present," verbal Dr Coates.

"The surprise for us was to look at the mass of these ions. known were several peaks reputation the spectrum, and when we analysed them we dictum the effect of water molecules clustering together one subsequent the other."

Dr Coates and colleagues invoice the Caps information in the journal Icarus. The measurments were made seeing the probe plunged now the plumes of Enceladus moment a close fly-by in 2008.

Caps found not proper the negatively charged water ions but hints of negatively charged hydrocarbons, over. indeed charged hydrocarbons at Enceladus lap up up-to-date been identified by Cassini's Ion and Neutral close with Spectrometer (INMS).

Where Caps has definitely seen negatively moved hydrocarbons is at Saturn's largest moon, Titan. There, live found colossal ions, some measuring more than 13,000 amu (an amu is roughly the draw of a single hydrogen atom).

"If you have a methane and nitrogen atmosphere besides you bombard it with particles from the Saturn's magnetosphere and ultraviolet coruscating from the Sun, you can cook up really alpine molecules,

" explained Dr Coates.
"They get bigger thanks to the altitude decreases. They are the source of Titan's vapour and also maybe the source of the dunes on the surface as they precipitate down."

Cassini is a joint venture between the US aperture agency (Nasa), the European space Agency (Esa) and the Italian Space Agency (ASI).