subsurface ocean Archives

Elemental maps of laboratory-frozen droplets containing major salt components expected in Enceladus' ocean. Each column shows the distribution of a different element, while the rows represent different cooling rates. At slower cooling rates, salts become increasingly separated into distinct regions within the droplets, particularly chloride salts associated with sodium and potassium. With faster cooling, the elements remain more uniformly distributed. These experiments show how slow freezing could produce the chemical segregation needed to explain the diverse ice grains detected by Cassini. Scale bars represent 50 micrometres. -- Science

How Enceladus’ Ocean Spray Becomes Chemically Diverse Ice Grains

by Keith CowingSeptember 30, 2026September 30, 2026

[Institute of Science Tokyo] Saturn’s icy moon Enceladus hides a global ocean beneath its frozen surface. From fractures near its south pole, material from this ocean is ejected into space […]

Icy Worlds

The Role of Disruptive Impacts on Ocean Generation and Longevity in Icy Moons

by Keith CowingAugust 21, 2026August 21, 2026

[Nature Astronomy] Among icy moons of the outer Solar System, subsurface water oceans and large collisions both seem to be common, but the impact of the latter on the presence […]

(Top) Measured OC albedo values from Goldstone (from Table 4) and (bottom) measured OC albedo values from the GBT (from Table 5). The horizontal dashed lines indicate the weighted means of the albedos, which is 0.90 for Goldstone and 0.80 for GBT. The error bars on our albedo values are taken to be the total uncertainty calculated in Section 4. The color bar on the right shows the dates of our observations in YYMMDD. The x-axis is the subradar point west longitude. -- [astro-ph.EP]

Europa

Radar Observations Of Europa in 2011-2024: New Insights Into Radar Scattering Properties

by Keith CowingAugust 20, 2026August 20, 2026

[astro-ph.EP] Three of Jupiter’s Galilean satellites – Europa, Ganymede, and Callisto – are of particular scientific interest due to their icy shells and suspected subsurface oceans. However, the radar properties […]

(a) Schematic of Europan ice-ocean system [related image in 11]. (b) Map of sea surface temperature (◦C) showing the transition between the temperature-stratified North Atlantic Ocean and the salt-stratified Arctic Ocean; (c) Potential temperature (left) and salinity (right) profiles with depth from location near the North Pole. Different water-mass characteristics are labeled. -- [astro-ph.EP]

Water/Hycean Worlds & Oceanography

What Can Planetary Ice Shells Teach Us about Ocean Mixing and Life, and Why Salt Matters

by Keith CowingAugust 12, 2026August 12, 2026

[astro-ph.EP] Past and present climates, both on Earth and in planetary systems, maintain ice covers with underlying oceans. This can range from sea ice in the Arctic Ocean to global […]

Larger image - Astrobiology.com/Grok/NASA

Europa

The Sulfate Content Of Europa’s Subsurface Ocean and Icy Shell

by Keith CowingAugust 9, 2026August 9, 2026

[Astrobiology (Journal)] Recent models for the origin of Jupiter indicate that the Galilean satellites were mostly derived from largely unprocessed solar nebula solids and planetesimals.

Jupiter

Joint Dynamical-geophysical Evidence For A Limit Cycle In The Galilean Moons

by Keith CowingAugust 7, 2026August 7, 2026

[astro-ph.EP] Io, Europa, and Ganymede orbit in the Laplace mean-motion resonance, where their orbital and thermochemical evolution are strongly coupled [1-5]. Forced eccentricities sustain tidal dissipation, powering Io’s volcanism and […]

Europa

Why Europa’s Hidden Ocean May Be More Difficult To Reach Than Scientists Thought

by Keith CowingJuly 25, 2026July 25, 2026

[Rutgers University] Europa, one of Jupiter’s icy moons, long has fascinated scientists because of what may lie beneath its frozen shell: a global ocean of liquid water.

The northern and eastern portions of Sputnik Planitia (SP)

Pluto

Evidence For Possible N2 Basal Flow Beneath Pluto Northern Sputnik Planitia

by Keith CowingJune 30, 2026June 30, 2026

[astro-ph.EP] Sputnik Planitia (SP) on Pluto is a large, predominantly N2 ice-filled basin with a surface area of one million square kilometers; it is among the most spectacular surface features […]

Coordinate systems. (a) Schematic of the coordinate systems. e𝜃 and er are the meridional (latitudinal) direction and the vertical direction (opposite to the gravitational direction), respectively. ez and es are the axial direction aligned with planetary rotation and the radial direction perpendicular to it, respectively. e𝜙 represents both the zonal direction in spherical coordinates and the azimuthal direction in cylindrical coordinates. (b) Distribution of 𝐻𝑧 in the simulation with Enceladus-like parameters: a core radius of 192 km and an ocean surface radius of 232 km. Outside the tangent cylinder, 𝐻𝑧 is kept constant. In (a) and (b), gray dashed lines indicate the tangent cylinder. -- astro-ph.EP

Astrogeology, Exoplanets, -moons, -comets, Icy Worlds, Water/Hycean Worlds & Oceanography

Parameterizing Slantwise Convection In Icy Moon Oceans

by Keith CowingJune 25, 2026June 25, 2026

Convection in icy moon oceans is strongly influenced by rotation, organizing into slantwise columnar structures aligned with the planetary rotation axis. They generate significant meridional heat transport, which can affect […]