In this composite image, red pixels mark locations on Europa’s surface where ammonia-bearing compounds were detected; purple indicates no such detection. Captured by NASA’s Galileo mission in 1997, the data is overlaid on a black-and-white mosaic that zooms in on a portion of the moon’s surface. NASA/JPL-Caltech

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Europa, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Press Release, Water/Hycean Worlds & Oceanography

NASA’s Galileo Mission Points to Ammonia at Europa, Recent Study Shows

by Keith CowingJanuary 29, 2026January 29, 2026

New analysis of decades-old data has turned up a significant result: the first discovery of ammonia-bearing compounds on the surface of Jupiter’s moon Europa. Ammonia is a nitrogen-bearing molecule, and […]

Jupiter's moon Europa was captured by the JunoCam instrument aboard NASA's Juno spacecraft during the mission's close flyby on Sept. 29, 2022. The images show the fractures, ridges, and bands that crisscross the moon's surface. Credit: Image data: NASA/JPL-Caltech/SwRI/MSSS Image processing: Björn Jónsson (CC BY 3.0)

Astrogeology, Europa, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Jupiter, Missions & Hardware, Press Release, Water/Hycean Worlds & Oceanography

Juno Measures The Thickness Of Europa’s Ice Shell

by Keith CowingJanuary 28, 2026

Results from the solar-powered spacecraft provide a new measurement of the thickness of the ice shell encasing the Jovian moon’s ocean.

Schematic diagram of typical initial conditions for a model run (not to scale). Temperature ranges from 100 to 273 K and is shown according to the color scale at right. There is an axis of symmetry on the right-hand side, adjacent to the denser and weaker “drip nucleus” region. The size, shape, density, and viscosity of the drip nucleus is varied between runs. Points labeled “X1,” “X2,” and “Y1” represent the locations of particle tracers tracked in Section 3 (results). Note that tracer particle “Y1” is at 300 m depth below the surface of the shell. Inset: depiction of “tapered” drip shape modeled in Section 4.2, with associated tracer particle locations. Inset shows the drip nucleus lithosphere against the symmetry boundary at the top of the model domain. -- The Planetary Science Journal

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Europa, Habitable Zones, Icy Worlds, Jupiter, Origin & Evolution of Life, Press Release, Radiation, Water/Hycean Worlds & Oceanography

Study Suggests A Pathway For Life-sustaining Conditions In Europa’s Ocean

by Keith CowingJanuary 21, 2026January 21, 2026

A recent study by geophysicists at Washington State University offers insight into how nutrients may reach the subsurface ocean of Europa, one of Jupiter’s moons and a leading candidate for […]

Astrochemistry, Astrogeology, Biosignatures & Paleobiology, Callisto, Europa, Ganymede, Icy Worlds, Io, Jupiter, Press Release

The Water Makeup Of Jupiter’s Galilean Moons Was Set At Birth

by Keith CowingJanuary 20, 2026January 20, 2026

While Io, the most volcanically active moon in the solar system, appears completely dry and devoid of water ice, its neighbor Europa is thought to harbor a vast global ocean […]

Schematic of the circum-Jovian decretion disk. Gas and dust from the circumsolar accretion disk are subsumed into the Jovian disk from approximately one hydrostatic scale height via meridional flows, and move outward beyond the magnetospheric truncation radius. Decretion M˙ is driven by turbulence manifesting as a macroscopic viscosity, and parametrized by the Shakura-Sunyaev α parameter. The four Galilean moons are envisioned to form beyond the ice-line and pressure bump, and undergo Type-I migration inwards. The bump serves as a migration trap, preventing Callisto from convergent migration into resonance with Io, Europa, and Ganymede. -- astro-ph.EP

Callisto, Europa, Ganymede, Icy Worlds, Io, Jupiter, Status Report

Callisto’s Nonresonant Orbit As An Outcome Of Circum-Jovian Disk Substructure

by Keith CowingJanuary 9, 2026January 9, 2026

The Galilean moons of Io, Europa, and Ganymede exhibit a 4:2:1 commensurability in their mean motions, a configuration known as the Laplace resonance.

Europa's possible ocean composition -- NASA

Arctic / Antarctic / Alpine, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Cryobiology, Europa, Habitable Zones, Icy Worlds, Jupiter, Press Release, Water/Hycean Worlds & Oceanography

Jupiter’s Moon Europa Has A Seafloor That May Be Quiet And Lifeless

by Keith CowingJanuary 7, 2026January 7, 2026

The giant planet Jupiter has nearly 100 known moons, yet none have captured the interest and imagination of astronomers and space scientists quite like Europa, an ice-shrouded world that is […]

The 0.6-GHz data are much brighter due to reflected synchrotron emission and are, therefore, shown with a different colour scale. The terminator was at approximately 10° W longitude, with the right-hand side in sunlight for these maps. The approximate sounding depth (50% contribution for pure, solid ice) is shown in the lower right of each map, and a typical beam size is shown in the lower left of each map. -- Nature

Analog Studies, Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Europa, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report

Europa’s Ice Thickness And Subsurface Structure Characterized By The Juno Microwave Radiometer

by Keith CowingJanuary 5, 2026January 2, 2026

Jupiter’s moon Europa is thought to harbour a saltwater ocean beneath a variously disrupted ice shell, and it is, thus, one of the highest priority astrobiology targets in the Solar […]

Surviving rapid inward orbital migration is a crucial aspect of formation models for the Jupiter's Galilean moons. (Source)

Callisto, Europa, Ganymede, Icy Worlds, Io, Jupiter, Status Report

Not Just Gas: How Solid-Driven Torques Shaped the Migration of the Galilean Moons

by Keith CowingDecember 31, 2025December 31, 2025

The primary aim of this study is to investigate the orbital migration of the Galilean moons by incorporating self-consistent solid dynamics in circumjovian disk models. We perform two-fluid simulations using […]