Iapetus – My WordPress Site

Major icy bodies in the Solar System, with the Earth’s moon to scale. The images are shown at the proper relative size. From NASA’s Planetary Photojournal (https://photojournal.jpl.nasa.gov/), Earth’s Moon (PIA00302), Europa (PIA00502), Ganymede (PIA00716), Callisto (PIA03456), Mimas (PIA06258), Enceladus (PIA06254), Tethys (PIA07738), Dione (PIA08256), Rhea (PIA08256), Titan (PIA08256), Hyperion (PIA07740), Iapetus (PIA08384), Phoebe (PIA06064), Miranda (PIA18185), Ariel (PIA01534), Umbriel (PIA00040), Titania (PIA01979), Oberon (PIA00034), Triton (PIA00317), Pluto (PIA19952). -- astro-ph.EP

Ariel, Astrogeology, Callisto, Ceres, Charon, Dione, Enceladus, Europa, Ganymede, Iapetus, Ice Giant, Icy Worlds, Mapping, Geodesy, Cartography, Mars, Mimas, Miranda, Missions & Hardware, Moon, Oberon, Phoebe, Pluto, Polar / Alpine Expeditions, Rhea, Tethys, Titan, Titania, Triton, Umbriel, Water/Hycean Worlds & Oceanography

Icy Worlds: Moons And Dwarf Planets

by Keith CowingDecember 1, 2025December 1, 2025

In the outer solar system beyond Jupiter, water ice is a dominant component of planetary bodies, and most solid objects in this region are classified as icy bodies.

The continuum-divided spectra of the Saturnian satellites, in the region of the O-D absorption. The red line shows a gaussian fit to the data using a fixed width. Most satellites have separate measurements for the leading and trailing hemispheres, but Hyperion and Phoebe, which are not synchronously rotating, only have single measurements. The O-D absorption is robustly detected at nearly every satellite. -- astro-ph.EP

Dione, Hyperion, Iapetus, Icy Worlds, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Mimas, Phoebe, Rhea, Saturn

Deuterated Water Ice On The Satellites Of Saturn

by Keith CowingOctober 17, 2025October 17, 2025

An average of the continuum-removed spectra of the leading and trailing hemispheres of Mimas and Tethys and the leading hemispheres of Dione and Rhea, in black, and of the trailing hemispheres of Dione and Rhea, in red. The lines at the bottom show measured wavelengths of CO2 in different states, including in pure crystalline form and trapped as clathrate in crystalline water ice (Oancea et al. 2012), trapped in amorphous ice (Sandford & Allamandola 1990; G´alvez et al. 2008) and physisorbed onto minerals (Hibbitts & Szanyi 2007), which can lead to a wide range of wavelengths. The shorter wavelength 4.2487 µm line associated with the darker hemispheres of Dione and Rhea appears to have no corresponding absorption in the 2.7 µm region. -- astro-ph.EP

Dione, Enceladus, Hyperion, Iapetus, Icy Worlds, Mimas, Phoebe, Rhea, Saturn, Tethys

A JWST Study Of CO2 On The Satellites Of Saturn

by Keith CowingOctober 6, 2025October 6, 2025