Cassini Study Finds 5 Salt Subtypes in 961 Enceladus Ice Grains
Updated
Updated · Sci.News · Sep 25
Cassini Study Finds 5 Salt Subtypes in 961 Enceladus Ice Grains
3 articles · Updated · Sci.News · Sep 25
Summary
Researchers analyzing 961 salt-rich ice grains from Saturn’s E ring found at least five chemical subtypes, overturning the idea that Enceladus’ ocean spray freezes into a single salty composition.
Lab freezing tests and thermodynamic modeling showed different salts precipitate at different temperatures when larger droplets cool slowly—below about 20 K per minute—separating chlorides, carbonates, phosphates and other compounds.
That points to a two-stage origin: tens-to-hundreds-of-micrometers droplets likely freeze inside Enceladus’ icy vents first, then shatter into the 1-2 micrometer grains Cassini detected in the plume and E ring.
The result suggests future missions should sample many individual plume grains rather than bulk material, because single particles could preserve concentrated ocean chemistry and potentially detectable biosignatures.