Europa Archives

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.

Planetary exploration is characterized by unknowns, which are both the primary reason and challenge for exploration.

Biosignatures & Paleobiology, Caves, Craters, Mountains, Subsurface, Lava Tubes, Comets and Asteroids, Exploration Gear & Tech, Habitable Zones, Imaging & Spectroscopy, Reports, Roadmaps, & Plans, Robotics/Rovers/UAVs, ROVs/Submersibles/Diving, Sample Return, Status Report, Tricorders & Sensors

Planetary Exploration 3.0: A Roadmap for Software-Defined, Radically Adaptive Space Systems

by Keith CowingApril 24, 2026April 24, 2026

The surface and subsurface of worlds beyond Mars remain largely unexplored. Yet these worlds hold keys to fundamental questions in planetary science – from potentially habitable subsurface oceans on icy […]

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, […]

An image taken by the Solid State Imager onboard the Galileo spacecraft showing the Rhadamanthys region, including its lineae and varied topography. The Rhadamanthys Lineae offer several examples of prominent double ridges, a few examples of which are labeled. Low albedo material is closely correlated with the topography for many ridges. For others, including the ridge cutting from northwest to southeast, reddening is more diffuse and can be found on the ridge margins. Note the pits in the top left of the image, which can also display varied amounts of reddening. Image from NASA/JPL-Caltech/University of Arizona.

Astrochemistry, Astrogeology, Europa, Icy Worlds, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Status Report

Thermal Segregation and Reddening in Europa’s Double Ridges

by Keith CowingApril 15, 2026April 15, 2026

Europa’s double ridges often display lower albedo and redder color than their surroundings. Their unique topography may cause sublimation-driven darkening due to illumination and self-heating, a process known as thermal […]

Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Enceladus, Habitable Zones, Origin & Evolution of Life, Status Report, Water/Hycean Worlds & Oceanography

From Early Earth to Enceladus – Mineral Electrochemistry Could Drive Organic Synthesis

by Keith CowingApril 13, 2026April 13, 2026

At some point in Earth’s history, chemistry transitioned from abiotic organic synthesis—the building of more complicated organic molecules from smaller ones by nonbiological means—to biochemistry.

Pressure–temperature (P–T) conditions of our experiments compared to phase diagram of the CO2–H2O system. Red dots correspond to actual P–T conditions at various stages of ice preparation. Dashed lines are only indicative and do not correspond to measured variations in pressure. Paths labeled in red, yellow, and magenta correspond to ice retaining CO2. Paths labeled in black correspond to ice devoid of CO2. Lowercase letters show the stages of the experiment described in the text, with subscripts showing the applicable experiment number. The stars near the bottom left denote the P–T conditions during acquisition of spectra. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Europa, Icy Worlds, Imaging & Spectroscopy, Status Report

The Fate Of Frozen Carbonated Water At Europa-like Conditions

by Keith CowingApril 13, 2026April 13, 2026

We present the results of experiments probing the retention of CO2 in crystalline water ice, frozen sodium chloride (NaCl) brines, and flash-frozen carbonated water using diffuse reflectance infrared spectroscopy.

Artist’s impression of the simulations conducted in this research. Jupiter (lower left) has a strong magnetic field which creates a cavity in its circumplanetary disk. Saturn (upper right) lacks a strong magnetic field so its circumplanetary disk evolves without a cavity. Credit: Yuri I. Fujii/L-INSIGHT [Kyoto University], Illustrator: Shinichiro Kinoshita

Astrogeology, Callisto, Enceladus, Europa, Ganymede, Gas Giants, Icy Worlds, Io, Jupiter, Magnetic Fields, Electromagnetism, bioelectricity,, Press Release, Rhea, Saturn, Titan, Water/Hycean Worlds & Oceanography

How Jupiter Cultivated More Large Moons Than Saturn

by Keith CowingApril 8, 2026April 8, 2026

The two largest planets in our Solar System, Jupiter and Saturn, also have the largest satellite systems, or the most moons. At present, Jupiter’s reported moon count stands at more […]

Four diagnostics of electron bombardment on Europa’s leading hemisphere: (a) total deposited-energy flux, (b) deposited-energy fraction, (c) mean secondary-electron energy, and (d) e-folding (≈ 63%) deposition depth. Cells with no electron flux in the relevant energy range are shown in gray. -- astro-ph.IM

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Interstellar, Status Report

Geant4-IcyMoons: Simulating Electron Interaction Physics in Irradiated Astrophysical Ices

by Keith CowingApril 3, 2026April 3, 2026

Energetic particles continuously process water ice across astrophysical and planetary environments, from interstellar clouds and comets to icy planetary surfaces. Interpreting the resulting observables requires a physically grounded description of […]

Europa

Identifying Amino Acid Isomers With Mass Spectrometry On Icy Ocean

Planetary Exploration 3.0: A Roadmap for Software-Defined, Radically Adaptive Space Systems

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

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

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

Thermal Segregation and Reddening in Europa’s Double Ridges

From Early Earth to Enceladus – Mineral Electrochemistry Could Drive Organic Synthesis

The Fate Of Frozen Carbonated Water At Europa-like Conditions

How Jupiter Cultivated More Large Moons Than Saturn

Geant4-IcyMoons: Simulating Electron Interaction Physics in Irradiated Astrophysical Ices

5 Questions About Astrobiology’s Future At NASA

The First Decade of Breakthrough Listen

Mars’ Oddest Cloud May Be Even Odder Than We Thought

A Technosignature Survey Of The Anti-Solar Point: The SETI Institute’s Largest-Ever Campaign With The Allen Telescope Array

Complex Organic Molecules in Protostars with ALMA Spectral Surveys (COMPASS) II. Approach To Data Reduction And Products For Line-rich Broadband (sub)millimeter Spectra