The water in Saturn's rings and satellites:

[beecee]

https://phys.org/news/2018-12-saturn-satellites-earth-moon-phoebe.html

The water in Saturn's rings and satellites is like that on Earth except for moon Phoebe, which is out of this world

December 3, 2018, Planetary Science Institute

Above image lower left: Cassini VIMS infrared view of Saturn. Blue is infrared light where water ice reflects relatively brightly. Red is longer wavelength thermal emission showing heat from deep inside the planet. Green is infrared wavelengths where aurora emit light. Above image upper right: Phoebe in visible light. Phoebe is very dark, like charcoal whereas the rings are very bright in visible light like slightly dirty snow. Phoebe is not to scale relative to Saturn. Credit: NASA, JPL, VIMS Team, ISS Team, U. Arizona, D. Machacek, U. Leicester

By developing a new method for measuring isotopic ratios of water and carbon dioxide remotely, scientists have found that the water in Saturn's rings and satellites is unexpectedly like water on the Earth, except on Saturn's moon Phoebe, where the water is more unusual than on any other object so far studied in the Solar System.

The results, found in the Icarus paper "Isotopic Ratios of Saturn's Rings and Satellites: Implications for the Origin of Water and Phoebe" by Planetary Science Institute Senior Scientist Roger N. Clark, also mean we need to change models of the formation of the Solar System because the new results are in conflict with existing models. Robert H. Brown (U. Arizona), Dale P. Cruikshank (NASA), and Gregg A. Swayze (USGS) are co-authors. 

Read more at: https://phys.org/news/2018-12-saturn-satellites-earth-moon-phoebe.html#jCp

the paper:

https://www.sciencedirect.com/science/article/abs/pii/S0019103518303580?via%3Dihub

Isotopic Ratios of Saturn's Rings and Satellites: Implications for the Origin of Water and Phoebe:

 

Abstract

Isotopic ratios have long been used to learn about physical processes acting over a wide range of geological environments, and in constraining the origin and/or evolution of planetary bodies. We report the spectroscopic detection of deuterium in Saturn's rings and satellites, and use these measurements to determine the (D/H) ratios in their near-surface regions. Saturn's moons, Phoebe and Iapetus, show a strong signature of CO₂ and the ¹³C component of this molecule is detected and quantified. Large averages of spectra obtained by the Cassini Visual and Infrared Mapping Spectrometer, VIMS, were computed for the rings and icy satellites. The observed intensities of the infrared absorptions in H₂O and CO₂and their isotopes were calibrated using laboratory data and radiative transfer models to derive the D/H and ¹³C/¹²C ratios. We find that the D/H in Saturn's rings and satellites is close to the Vienna Standard Mean Ocean Water (VSMOW) and bulk Earth (4% lower than VSMOW) value except for Phoebe, which is 8.3 times the VSMOW value. This is the highest value for any Solar-System surface yet measured, and suggests that Phoebe formed from material with a different D/H ratio than the other satellites in the Saturn system. Phoebe's ¹³C/¹²C ratio is also unusual: 4.7 times greater than terrestrial, and greater than values measured for the interstellar medium and the galactic center. The high ¹³C abundance in the CO₂ suggests that Phoebe was never warm enough for the large D/H ratio in its surface to have originated by evaporative fractionation of its water ice (e.g., from heating in the inner Solar System before its eventual capture by Saturn). We also report the detection of a probable O-D stretch absorption due to OD in minerals on Phoebe at 3.62 μm. This absorption is not detected on other Saturnian satellites. Stronger signatures of bound water absorptions are found in the dark material of Iapetus and we report a new detection of bound water at 1.9 μm. The position of this absorption matches that seen in spectra of hydrated iron oxides but does not match absorptions seen in spectra of tholins. Despite the strong bound water signature in the Iapetus dark material, no 3.62-μm OD absorption is seen in the spectra, further indicating the high deuterium level on Phoebe is unusual. As such, it is likely that Phoebe originated in a colder part of the outer Solar System, relative to the prevailing temperatures at Saturn's distance from the Sun.