Jupiter Archives

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 […]

[RIGHT Io [LEFT] Europa -- NASA JPL source

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Europa, Icy Worlds, Io, Jupiter, Lava / magma ocean / Volcanic Worlds, Mapping, Geodesy, Cartography, Bathymetry, Status Report, Water/Hycean Worlds & Oceanography

On The Divergent Evolution Of Io And Europa As Primordial Ocean Worlds

by Keith CowingDecember 22, 2025December 22, 2025

Galilean moons exhibit a decrease in bulk density with distance from Jupiter, which may reflect differences in evolutionary paths and water loss.

Global distribution of the four major nonwater species in Europa’s surface ice with reaction rate coefficients scaled down by a factor of 10. (a) H2SO4. (b) SO2. (c) H2O2. (d) O2. -- astro-ph.EP

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

Global Distribution Of The Key Species on the Surface of Europa

by Keith CowingNovember 13, 2025November 13, 2025

The icy surface of Europa is continuously bombarded by ions and electrons from Jupiter’s magnetosphere.

The four giant planets as seen by Hubble WFC3/UVIS at different near-UV wavelengths, and processed by Judy Schmidt (note - these images are not shown to scale). The Jupiter and Saturn images are constructed from F343N (red), F275W (green), and F225 (blue), whereas a lack of observations for Uranus and Neptune required us to shift to redder wavelengths: F547M (red), F467M (green), and F336W (blue) for the Ice Giants. Jupiter and Ganymede were observed 2017-02-02 at 12:16UT, Saturn was observed at 2018-06-07 at 00:06UT, Uranus on 2015-08-30 at 10:08UT, and Neptune on 2015-09-02 at 07:58UT. Strong UV absorption is visible at the poles of Jupiter and Saturn due to the nature of highaltitude aerosols and the potential link to auroral chemistry. Red vortices, such as Jupiter’s Great Red Spot and Oval BA (lower left), appear dark due to the blue-absorbing chromophore responsible for their red colours. Uranus’ bright north polar cap of aerosols, and its narrow rings, are just visible in this image. Neptune’s banding, and some bright high clouds (appearing in pink) can be seen in both northern and southern hemispheres. In addition, Saturn’s rings appear reddish due to UV absorption. Credit: NASA/ESA/CSA/Hubble/Judy Schmidt.

Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Ice Giant, Imaging & Spectroscopy, Jupiter, Neptune, Saturn, Status Report, Uranus

Exploring Giant Planet Atmospheres with Habitable Worlds Observatory

by Keith CowingOctober 22, 2025October 22, 2025

Visible and ultraviolet imaging and spectroscopy of Solar System giant planets can set the paradigm for the atmospheric, ionospheric, and magnetospheric processes shaping the diversity of giant exoplanets, brown dwarfs, […]

Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exploration Gear & Tech, Gas Giants, Imaging & Spectroscopy, Jupiter, Robotics/Rovers/UAVs, Saturn, Video, Audio, Webcasts, Podcasts, Water/Hycean Worlds & Oceanography

Video: A Preview Of Future Gas Giant Exploration

by Keith CowingAugust 18, 2025August 18, 2025

Imagine what a future Astrobiology droid might see as it flies through clouds on Jupiter or Saturn looking for biosignatures.

Analysis of exospheric ice grains at Europa by SUDA.

Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Cryobiology, Europa, Exoplanets, -moons, -comets, Icy Worlds, Imaging & Spectroscopy, Jupiter, Mapping, Geodesy, Cartography, Bathymetry, Missions & Hardware, Robotics/Rovers/UAVs, Sample Return, Status Report, Water/Hycean Worlds & Oceanography

Replicating The Flyby Sampling Of Salty Ocean World Ice Grains Using Impact Ionization Mass Spectrometry

by Keith CowingAugust 15, 2025August 15, 2025

The Europa Clipper mission will arrive at the Jovian system in 2030 and analyze ice grains sourced from the icy material on its surface using impact mass spectrometry, which will […]

The north polar region of Jupiter’s volcanic moon Io was captured by the JunoCam imager aboard NASA’s Juno during the spacecraft’s 57th close pass of the gas giant on Dec. 30, 2023. A technique called annealing was used to help repair radiation damage to the camera in time to capture this image. Credit: Image data: NASA/JPL-Caltech/SwRI/MSSS. Image processing by Gerald Eichstädt Full Image Details

Exploration Gear & Tech, Imaging & Spectroscopy, Jupiter, Missions & Hardware, Press Release

How To Save A Spacecraft Camera 370 Million Miles Away In Jupiter Orbit

by Keith CowingJuly 22, 2025July 22, 2025

An experimental technique rescued a camera aboard the agency’s Juno spacecraft, offering lessons that will benefit other space systems that experience high radiation.