We’ve seen the fun festive dance of Saturn’s moons, but the BBC reports the latest confirmation of the briny breath of Enceladus – courtesy of the Cassini Plasma Spectrometer. And, from the Cassini press release
“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,” said lead author Andrew Coates from University College London’s Mullard Space Science Laboratory. “The surprise for us was to look at the mass of these ions. There were several peaks in the spectrum, and when we analyzed them we saw the effect of water molecules clustering together one after the other.” The measurements were made as Cassini plunged through Enceladus’ plume on March 12, 2008.
At Titan, the same instrument detected extremely large negative hydrocarbon ions with masses up to 13,800 times that of hydrogen. A paper in Planetary and Space Science by Coates and colleagues in December 2009. They found showed that, at Titan, the largest hydrocarbon or nitrile ions are seen at the lowest altitudes of the atmosphere that Cassini flew (950 kilometers, or 590 miles). They suggest these large ions are the source of the smog-like haze that blocks most of Titan’s surface from view. They may be representative of the organic mix called “tholins” by Carl Sagan when he produced the reddish brew of prebiotic chemicals in the lab from gases that were known to be present in Titan’s atmosphere. Tholins that may be produced in Titan’s atmosphere could fall to the moon’s surface and may even make up the sand grains of the dunes that dominate part of Titan’s equatorial region. The findings add to our growing knowledge about the detailed chemistry of Enceladus’ plume and Titan’s atmosphere, giving new understanding of environments beyond Earth where pre-biotic or life-sustaining environments might exist.