Titania Archives

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’ […]