Two-dimensional temperature map of the disk after 280 kyr of evolution. The averaged trajectories of particles over this period, plotted along the 𝑟 and 𝑧 axes, are shown in white. The panels present the trajectories of particles with sizes of 1 cm and 1 𝜇m, released at initial disk temperatures of 20 K (panels a and b) and 80 K (panels c and d). Green triangles indicate the initial positions of the particles, while green crosses mark their final positions. In each panel, the detailed trajectory of an individual particle is highlighted within the square on the right. -- astro-ph.EP

Astrochemistry, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Callisto, Europa, Ganymede, Icy Worlds, Imaging & Spectroscopy, Io, Jupiter, Status Report

Delivery Of Complex Organic Molecules To The System Of Jupiter

by Keith CowingFebruary 20, 2026February 20, 2026

Complex organic molecules are key markers of molecular diversity, and their formation conditions in protoplanetary disks remain an active area of research. These molecules have been detected on a variety […]

Temperature profiles of the CPD at t = 50, 100, 150, and 200 kyr of its evolution. The formation of COMs by thermal processing occurs in the temperature range from 80 K (blue dashed line) to 260 K (red dashed line). At 150 kyr of evolution, a cold region appears in the model, with temperatures too low to support COM formation by thermal processing. -- astro-ph.EP

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Callisto, Cryobiology, Europa, Ganymede, Habitable Zones, Ice Giant, Io, Jupiter, Missions & Hardware, Status Report

Formation and Survival of Complex Organic Molecules in the Jovian Circumplanetary Disk

by Keith CowingFebruary 19, 2026February 19, 2026

Europa, Ganymede, and Callisto are key targets in the search for habitability due to the potential presence of subsurface oceans. Detecting complex organic molecules (COMs), essential for prebiotic chemistry, is […]

The Pale Blue Dot is a photograph of Earth taken Feb. 14, 1990, by NASA’s Voyager 1 at a distance of 3.7 billion miles (6 billion kilometers) from the Sun. The image inspired the title of scientist Carl Sagan's book, "Pale Blue Dot: A Vision of the Human Future in Space," in which he wrote: "Look again at that dot. That's here. That's home. That's us." The above image, “Pale Blue Dot Revisited,” was created in 2020 for the 30th anniversary of the iconic picture. The updated version used modern image-processing software and techniques to revisit the well-known Voyager view, while attempting to respect the original data and intent of those who planned the images. NASA/JPL-Caltech Larger image

Imaging & Spectroscopy, Interstellar, Jupiter, Mars, Mercury, Neptune, Press Release, Uranus, Venus

Pale Blue Dot Anniversary

by Keith CowingFebruary 14, 2026February 14, 2026

The Pale Blue Dot is a photograph of Earth taken on Feb. 14, 1990, by NASA’s Voyager 1 spacecraft. Earth appears as a tiny speck of light suspended in a […]

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 […]

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 […]