Oberon Archives

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, Bathymetry, Mars, Mimas, Miranda, Missions & Hardware, Moon, Oberon, Phoebe, Pluto, Polar / Alpine Expeditions, Rhea, Status Report, 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.

Uranus and its four largest moons -- NASA

Ariel, Astrochemistry, Astrogeology, Ice Giant, Icy Worlds, Imaging & Spectroscopy, Oberon, Press Release, Titania, Umbriel, Uranus

The Moons of Uranus Surprise Scientists

by Keith CowingJune 12, 2025

Scientists using NASA’s Hubble Space Telescope went looking for evidence of one phenomenon and found quite another. The research team studied the four largest moons of the ice giant Uranus, […]

Magnetic field of Uranus. (left) Magnetic field line geometry of Uranus for Winter Solstice and Spring Equinox in the Uranus–Sun–Orbit frame. The orbits of Miranda, Ariel, Umbriel, Titania and Oberon are shown. Independent of season, the magnetic field of Umbriel (as well as Miranda and Ariel) is well shielded from external effects of the magnetosphere, making it a robust target for magnetic induction investigation of its interior (right) Fourier transform of the magnetic field of Uranus evaluated at the position of Umbriel. Note that although there are many beats and harmonics of the two fundamental frequencies, only the synodic is used here for characterization owing to its dominance over the other frequencies. -- Philos Trans A Math Phys Eng Sci via PubMed

Ariel, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Europa, Exploration Gear & Tech, Ganymede, Ice Giant, Icy Worlds, Magnetic Fields, Electromagnetism, bioelectricity,, Miranda, Oberon, Status Report, Titania, Umbriel, Uranus, Water/Hycean Worlds & Oceanography

Detecting Planetary Oceans: Application To The Uranus System

by Keith CowingDecember 8, 2024May 12, 2025

The discovery of Europa’s subsurface ocean has spawned a strong desire by the planetary community to return and assess the ocean’s habitability using the magnetic induction signal that Europa generates.

Ariel, Astrogeology, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Habitable Zones, Ice Giant, Icy Worlds, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Miranda, Oberon, Press Release, Titania, Umbriel, Uranus, Water/Hycean Worlds & Oceanography

Uranus’ Swaying Moons Will Help Spacecraft Seek Out Hidden Oceans

by Keith CowingNovember 29, 2024May 12, 2025

When NASA’s Voyager 2 flew by Uranus in 1986, it captured grainy photographs of large ice-covered moons. Now nearly 40 years later, NASA plans to send another spacecraft to Uranus, […]

An artist’s impression of Uranus and its five largest moons (innermost to outermost) Miranda, Ariel, Umbriel, Titania and Oberon. Credit: NASA/Johns Hopkins APL/Mike Yakovlev

Ariel, Biosignatures & Paleobiology, Habitable Zones, Icy Worlds, Miranda, Oberon, Status Report, Titania, Umbriel, Uranus

The Astrobiological Potential of the Uranian Moon System

by Keith CowingAugust 27, 2024August 27, 2024

The 2023-2032 Planetary Science and Astrobiology Decadal Survey prioritized the Uranus Orbiter and Probe (UOP) mission concept as the next priority flagship mission. The UOP concept includes scientific studies of […]

JWST NIRCam albedos of Proteus and Puck compared to the spectra of 2004 EW95 (Plutino) and 2007 VL305 (Neptune Trojan) from JWST Programs 2418 and 2550 respectively. Also shown are Voyager-derived visual geometric albedos, with the Puck albedo selected to be at the same phase angle as the JWST observations (see Figure 6 of Karkoschka (2001) and Table 2 of Karkoschka (2003)). The spectrophotometry for Proteus and Puck closely matches the shape and albedo for the selected objects, both of which have less red/neutral spectral slopes, and perihelia also near 30AU. Higher resolution spectra for Puck and Proteus are needed to reveal surface composition. -- astro-ph.EP

Astrochemistry, Astrogeology, Biosignatures & Paleobiology, Icy Worlds, Imaging & Spectroscopy, Miranda, Neptune, Oberon, Status Report, Titania, Triton, Umbriel, Uranus

JWST Spectrophotometry of the Small Satellites of Uranus and Neptune

by Keith CowingApril 11, 2024April 11, 2024

We use 1.4-4.6 micron multi-band photometry of the small inner Uranian and Neptunian satellites obtained with the James Webb Space Telescope’s near-infrared imager NIRCam to characterize their surface compositions.

Frequency band available for passive sounding for each icy moon. The upper value of 900 kHz is due to the cutoff frequency of the UKR source. The green bar extends down to the plasma frequency upper limit derived from scaling to Europa’s peak ionospheric electron densities ( Figure 7) and scale heights. These upper limits are aggressively pessimistic given that, unlike Europa, Uranian icy moons do not reside in a plasma torus nor are they expected to be active. The yellow bars cover the uncertain range between the plasma frequency upper limit and the ambient plasma frequency in the Uranian system (f ' 9 kHz). Even with these pessimistic upper bounds, a significant portion of the spectrum of UKR emissions penetrate through the icy moon ionospheres and allows for passive sounding. -- astro-ph.EP

Ariel, Icy Worlds, Miranda, Oberon, Press Release, Titania, Umbriel, Uranus

Feasibility of Passive Sounding of Uranian Moons using Uranian Kilometric Radiation

by Keith CowingMay 9, 2023December 18, 2023

We present a feasibility study for passive sounding of Uranian icy moons using Uranian Kilometric Radio (UKR) emissions in the 100 – 900 kHz band.

New modeling shows that there likely is an ocean layer in four of Uranus’ major moons: Ariel, Umbriel, Titania, and Oberon. Salty – or briny – oceans lie under the ice and atop layers of water-rich rock and dry rock. Miranda is too small to retain enough heat for an ocean layer. Credit: NASA/JPL-Caltech

Ariel, Icy Worlds, Miranda, Oberon, Press Release, Titania, Umbriel, Uranus, Water/Hycean Worlds & Oceanography

A New Study of Uranus’ Large Moons Shows That Four May Hold Water

by Keith CowingMay 4, 2023December 18, 2023

Re-analysis of data from NASA’s Voyager spacecraft, along with new computer modeling, has led NASA scientists to conclude that four of Uranus’ largest moons likely contain an ocean layer between […]

Ariel, Icy Worlds, Miranda, Oberon, Press Release, Titania, Umbriel, Uranus

In Search Of Subsurface Oceans Within The Uranian Moons

by Keith CowingMay 13, 2021October 30, 2024

The Galileo mission to Jupiter discovered magnetic signatures associated with hidden sub-surface oceans at the moons Europa and Callisto using the phenomenon of magnetic induction. These induced magnetic fields originate […]

Ariel, Icy Worlds, Miranda, Oberon, Press Release, Titania, Umbriel, Uranus

The Science Case For Spacecraft Exploration Of The Uranian Satellites: Candidate Ocean Worlds In An Ice Giant System

by Keith CowingMay 5, 2021October 30, 2024

The 27 satellites of Uranus are enigmatic, with dark surfaces coated by material that could be rich in organics. Voyager 2 imaged the southern hemispheres of Uranus’ five largest ‘classical’ […]