Europa Archives

The plumes of Enceladus - NASA/JPL-Caltech/Space Science Institute Larger image

Biosignatures & Paleobiology, Enceladus, Europa, Habitable Zones, Icy Worlds, Press Release, Water/Hycean Worlds & Oceanography

A Framework For Evaluating Biosignature Potential Against The Abiotic Baseline On Ocean Worlds

by Keith CowingMay 18, 2026May 18, 2026

Ocean worlds are considered as targets for life detection missions because they meet several key requirements for habitability. However, identifying potential life on other worlds requires observing clear and unambiguous […]

Juice-UVS saw gas and dust elements stretching up to more than 5 million km from 3I/ATLAS’s nucleus on November 25, 2025, when the comet had dimmed considerably relative to November 2 observations. Black spots are where stars appeared in the scanned image, removed here for clarity. Credit: NASA/ESA/Southwest Research Institute

Astrochemistry, Astrogeology, Comets and Asteroids, Europa, Icy Worlds, Imaging & Spectroscopy, Missions & Hardware, Press Release

Two Spacecraft Observed Both Hemispheres Of Interstellar Comet 3I/ATLAS Simultaneously

by Keith CowingMay 14, 2026May 14, 2026

The Southwest Research Institute-led Ultraviolet Spectrograph (UVS) instruments aboard ESA’s Jupiter Icy Moons Explorer (Juice) spacecraft and NASA’s Europa Clipper made unique observations of interstellar comet 3I/ATLAS in late 2025. […]

Graphical Abstract -- Ice grains emitted by the Saturnian moon Enceladus were sampled by Cassini’s Cosmic Dust Analyser (CDA) using impact ionization mass spectrometry. -- ACS Earth Space Chem

Biosignatures & Paleobiology, Comets and Asteroids, Cryobiology, Dione, Enceladus, Europa, Ganymede, Habitable Zones, Hyperion, Iapetus, Icy Worlds, Mimas, Oberon, Status Report, Titan

Quantum Chemical Insights into the Dissociation of Phenol: Shedding Light on Impact Ionization Mass Spectrometry for Icy Moon Exploration

by Keith CowingMay 11, 2026May 11, 2026

CDA revealed that Enceladus hosts a rich organic and inorganic chemical inventory in its subsurface ocean, hinting at its potential habitability. Analysis of fragmentation patterns with laser desorption experiments for […]

Titan is an abode of NH3. (A) Titan captured by the Cassini Imaging Science Subsystem. The thick atmosphere of Titan is visible by a haze across the surface and a lack of surface details. Saturn’s other moon, Tethys, is observed behind Titan. Image credits: NASA/JPL-Caltech/Space Science Institute. (B) False-colour mosaic of Titan obtained by the Visual and Infrared Mapping Spectrometer of Cassini. Colours correspond to atmospheric (red) and surface features (green and blue). The inset image indicates the possible occurrence of a cryovolcano on the surface. Cryovolcanic slurries of water, NH3, and methanol have been tentatively observed on the surface. Image credit: NASA/JPL/University of Arizona.

Enceladus, Europa, Ganymede, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Jupiter, Saturn, Status Report, Titan

Ammonia As A Parameter Shaping Habitability On Icy Moons

by Keith CowingMay 6, 2026May 6, 2026

The search for life now extends beyond the traditional habitable zone to include the icy moons of Jupiter and Saturn. These moons feature ice-covered surfaces overlying substantial oceans formed primarily […]

Time-resolved IR spectra from electron irradiation of CaCO3 at 50, 100, and 120 K under two electron fluxes, normalized to the preirradiation CaCO3 baseline and truncated to the 4.2–4.3 μm region to highlight the CO2 ν3 band. Vertical dashed lines mark the central wavelengths of the CO2 doublet, determined from double Gaussian fits to the continuum-removed spectra (gray). CO2 absorptions appear upon irradiation and gradually saturate. The strongest absorptions occur at 50 K under high flux. At higher temperatures, the absorptions are weaker, but radiolytic CO2 production is still apparent. -- astro-ph.EP

Astrochemistry, Astrogeology, Europa, Icy Worlds, Imaging & Spectroscopy, Status Report

Formation And Trapping Of CO2 From Cryogenic Irradiation Of Carbonate

by Keith CowingMay 2, 2026May 2, 2026

The detection of CO2 on the Jovian satellite Europa by Galileo NIMS and recent mapping of the leading side by JWST has revealed that it is most concentrated in geologically […]

LILBID cationic mass spectrum of l-norleucine simulating an impact velocity of 5–7 km/s. The protonated molecular peak of l-norleucine is labeled “M+H+.” Fragment ions are identified in the mass spectrum and represented in the molecular structure as well. Ions from the matrix (pure water clusters and sodium and potassium water clusters) are labeled with blue triangles and yellow and green squares. -- Astrobiology via x-mol.net

Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Enceladus, Europa, Exploration Gear & Tech, Extremeophiles and Extreme Environments, Genomics, Proteomics, Bioinformatics, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report, Tricorders & Sensors

Identifying Amino Acid Isomers With Mass Spectrometry On Icy Ocean

by Keith CowingApril 27, 2026April 27, 2026

Enceladus and Europa are compelling targets for astrobiology investigations due to their potentially habitable subsurface oceans connected to the icy surface by geological processes.

(A) Schematic of the ice growth apparatus. (B) Image of the ice growth apparatus shortly after the onset of an experiment. (C) The ~50-cm-thick Europa 2 ice column immediately after extraction. The column is placed upside down to reduce brine loss from the highly porous basal region of the ice. (D) Ice columns subsectioned into smaller, more easily workable pieces and scored at 2-cm intervals in preparation for vertical partitioning. (E) The scored subsections in (D) were cut using an electric band saw, and the 2-cm layers were placed into 500-ml high-density polyethylene amber Nalgene sample bottles. These samples were subsequently melted, filtered, and processed via IC, ICP-OES, and NDIR spectroscopy to acquire our ionic composition and ionic fractionation profiles. -- Science Advances via PubMed

Analog Studies, Arctic / Antarctic / Alpine, Astrogeology, Biogeochemical Cycles & Geobiology, Cryobiology, Enceladus, Europa, Exploration Gear & Tech, Ganymede, Icy Worlds, Mapping, Geodesy, Cartography, Bathymetry, Polar / Alpine Expeditions, Robotics/Rovers/UAVs, Status Report, Water/Hycean Worlds & Oceanography

As Above, Not So Below: Ion Fractionation In Planetary Analog Ices

by Keith CowingApril 25, 2026April 25, 2026

The geophysical evolution and astrobiological potential of ocean worlds are indelibly linked to the chemical compositions of their oceans and ice shells.

Sky map of the Lyα brightness seen from Europa for visit 12 (Jan 26, 2015) from interplanetary medium H scattering model (Pryor et al. 2024). The direction to the Sun is shown by the small white circle, the anti-Sun direction is shown by the white asterisk. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Europa, Icy Worlds, Imaging & Spectroscopy, Space Weather & Heliophysics, Status Report

Europa’s Lyman-α Emissions From HST/STIS Observations

by Keith CowingApril 23, 2026April 23, 2026

Context. An image of Lyman-α (Lyα) emission from Europa obtained with the Hubble Space Telescope’s Space Telescope Imaging Spectrograph (HST/STIS) provided the first evidence for localized water vapor (H2O) aurora, […]

Bond albedo (a) and thermal inertia (b) maps derived from PPR measurements in this study. Background is the USGS Europa Voyager Galileo SSI Global Mosaic of Europa (Becker et al. 2010). -- astro-ph.EP

Analog Studies, Arctic / Antarctic / Alpine, Europa, Icy Worlds, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Status Report, Water/Hycean Worlds & Oceanography

Thermophysical Properties of Europa’s Surface Constrained by Galileo Photopolarimeter-Radiometer Temperature Measurements

by Keith CowingApril 18, 2026April 18, 2026

Thermal measurements constrain the physical properties of icy satellite surfaces, including grain size, porosity, and regolith structure. On Europa, analyses of the Galileo Photopolarimeter-Radiometer (PPR) dataset revealed thermal inertia heterogeneities, […]

Interior, surface and atmosphere visualisation of Europa, Enceladus, Triton, Io, and exoIo. Best-estimate plume heights are displayed to scale. Individual scales are visible for interior structures. -- astro-ph.EP

Astrogeology, Biosignatures & Paleobiology, Enceladus, Europa, Exoplanets, -moons, -comets, Icy Worlds, Io, Lava / magma ocean / Volcanic Worlds, Status Report, Triton, Water/Hycean Worlds & Oceanography

Active Moons In Our Solar System And Beyond — Io, Europa, Enceladus, Triton, and Exomoons

by Keith CowingApril 15, 2026April 15, 2026

The outgassing signatures of Io, Europa, Enceladus, Triton, and Io-like exomoons are the focus of this review chapter. The rocky volcanic world of Io is unique in our Solar System, […]