Some of 'the major ingredients for life' are present on one of Saturn's moons, according to University College London scientists.

A team from the Mullard Space Science Laboratory working on the Cassini-Huygens mission have found negatively charged water ions in the ice plume of Enceladus.

The spacecraft's plasma spectrometer, used to gather this data, also found other species of negatively charged ions including hydrocarbons.

MSSL's Professor Andrew Coates, lead author of a paper on the latest discovery, said: "While it's no surprise that there is water there, these short-lived ions are extra evidence for sub-surface water and where there's water, carbon and energy, some of the major ingredients for life are present.

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

Enceladus thus joins Earth, Titan and comets where negatively charged ions are known to exist in the solar system. Negative oxygen ions were discovered in Earth's ionosphere at the dawn of the space age. At Earth's surface, negative water ions are present where liquid water is in motion, such as waterfalls or crashing ocean waves.

The plasma spectrometer measures the density, flow velocity and temperature of ions and electrons that enter the instrument. But since the discovery of Enceladus' water ice plume, the instrument has also successfully captured and analysed samples of material in the jets.

Early in its mission, Cassini-Huygens discovered the plume that fountains water vapour and ice particles above Enceladus. Since then, scientists have found that these water products dominate Saturn's magnetic environment and create Saturn's huge E-ring.

"Cassini captured this stunning mosaic of Enceladus as the spacecraft sped away from the geologically active moon of Saturn. (Credit: NASA)"

Source: University College London