![(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]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Radar-observations.png?resize=1200%2C751&ssl=1)
[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 […]
Europa
![(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]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/What-can.png?resize=1200%2C582&ssl=1)
Posted inWater/Hycean Worlds & Oceanography
What Can Planetary Ice Shells Teach Us about Ocean Mixing and Life, and Why Salt Matters
[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 […]
Posted inEuropa
The Sulfate Content Of Europa’s Subsurface Ocean and Icy Shell
[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.
Posted inJupiter
Joint Dynamical-geophysical Evidence For A Limit Cycle In The Galilean Moons
[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 […]
![This artist’s concept depicts a cutaway view showing Europa’s ice shell. Data used to generate a new result on the ice thickness and structure was collected by the microwave radiometer instrument on NASA’s Juno during a close flyby of the Jovian moon on Sept. 29, 2022. NASA/JPL-Caltech/SwRI/Koji Kuramura/ Gerald Eichstädt (CC BY) [Enhanced by Grok via Astrobiology.com]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Why-Europa.jpg?resize=1200%2C752&ssl=1)
Posted inEuropa
Why Europa’s Hidden Ocean May Be More Difficult To Reach Than Scientists Thought
[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.
Posted inJupiter
The Recent Crossing Of The 7:3 Resonance Between Ganymede And Callisto
[astro-ph.EP] Io, Europa and Ganymede are locked in the well-known Laplace resonance, while Callisto is not, even though it is very close to the 7:3 mean motion resonance with Ganymede. […]
Posted inEuropa
VLBI Tracking of the JUICE Mission: Two Years of Cruise Phase Operations and Performance Analysis
[physics.space-ph] The JUpiter ICy moons Explorer (JUICE) mission, launched by the European Space Agency (ESA) in April 2023, represents one of the most ambitious deep space exploration endeavours targeting Jupiter’s […]
Posted inIcy Worlds
Dynamic Controls On Subsurface Water Chemistry And Habitability On Icy Moons
Icy moons are natural satellites whose surfaces contain a substantial fraction of frozen materials, most notably water ice.
Posted inEuropa, Meteorites & Asteroids, Origin & Evolution of Life, Panspermia, Planetary Protection & Biosafety, Status Report, Water/Hycean Worlds & Oceanography
Earth As A Potential Source Of Llife For Europa’s Subsurface Ocean
The paper discusses the possibility of dust particles containing living bacteria ejected from Earth reaching Europa and landing on its surface.
Posted inAtmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Cryobiology, Europa, Extremeophiles and Extreme Environments, Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Origin & Evolution of Life, Press Release
Probing The Habitability Of Potential Sulfuric Acid Rich Subsurface Lakes In Europa’s Ice Shell Via Saci/STIV Integrated Models
Experimentally modeling the habitability of extreme ocean world conditions, such as those on Jupiter’s moon: Europa, would benefit from integrated microbe-virus model studies to provide both a microbial model and […]