Jupiter Archives

Comparing CO2 exosphere to surface properties on Ganymede’s leading hemisphere. A) Vertical CO2 gas column density (unit of 1018 m−2 , this work, see also Fig. O.2); B) Depth of CO2-solid absorption band (Paper I); C) Central wavelength of CO2-solid absorption band (Paper I); D) Reflectance at 3.65 µm (Paper I); E) Central wavelength of H2O Fresnel peak (Paper I); F) Relative amplitude of the maximum reflectance between 3.5 and 4 µm (H2O interband amplitude, Paper I). The north pole of the leading hemisphere possesses the most red-shifted absorption band center of solid CO2, consistent with CO2 trapped in amorphous H2O ice (Paper I). It also has the higher reflectance at 3.65 µm and H2O interband amplitude, indicative of a higher density of facets in H2O ice for the photons (i.e., smaller grains and/or more internal defects and/or higher micro-roughness/porosity), and the most blue-shifted central wavelength of the H2O Fresnel peak due to a higher proportion of amorphous water ice (Mastrapa et al. 2009). -- astro-ph.EP

Astrochemistry, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Cryobiology, Ganymede, Icy Worlds, Jupiter, Status Report

A Patchy CO2 Exosphere On Ganymede Revealed By The James Webb Space Telescope

by Keith CowingSeptember 23, 2024September 23, 2024

Jupiter’s icy moon Ganymede has a tenuous exosphere produced by sputtering and possibly sublimation of water ice. To date, only atomic hydrogen and oxygen have been directly detected in this […]

Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Europa, Habitable Zones, Icy Worlds, Jupiter, Missions & Hardware, Press Release, Water/Hycean Worlds & Oceanography

8 Things To Know About NASA’s Astrobiology Mission To Ocean World Europa

by Keith CowingSeptember 17, 2024September 17, 2024

The first NASA spacecraft dedicated to studying an ocean world beyond Earth, Europa Clipper aims to find out if the ice-encased moon Europa could be habitable.

Artist’s rendition of variety of exoplanets featured in the new NASA TESS-Keck Survey Mass Catalog, the largest, single, homogenous analysis of TESS planets released by any survey thus far. Credit: W. M. Keck Observatory/Adam Makarenko

Alpha Centauri, Astrogeology, Beta Pictoris, Ceres, Exoplanets, -moons, -comets, Gas Giants, Icy Worlds, Jupiter, Lava / magma ocean / Volcanic Worlds, Mapping, Geodesy, Cartography, Bathymetry, Mars, Mercury, Neptune, Pluto, Proxima Centauri, Saturn, Status Report, tau Ceti, TRAPPIST-1, Uranus, Venus, Water/Hycean Worlds & Oceanography

Classifications For Exoplanet and Exoplanetary Systems

by Keith CowingSeptember 17, 2024September 17, 2024

When a star is described as a spectral class G2V, we know its approximate mass, temperature, age, and size. At more than 5,700 exoplanets discovered, it is a natural developmental […]

Above: Examples of typical surfaces of the icy Galilean satellites (panel a: Europa, near Conamara Chaos region at 8.1°N/90.9°E; panel b: Ganymede, Nicholson Regio at ∼14°S/12.7°E; panel c: Callisto, detail of Asgard impact basin at 14.7°N/218°E). All images are scaled to 150 m px−1. The crater density (a proxy of surface age) increases from Europa to Callisto, reflecting the geological history of surface processes. The surface of Europa displays the most complex inventory of landforms that were formed by endogenic processes, whereas Callisto’s surface is almost devoid of any evidence for tectonic and cryovolcanic activity (Image: NASA/DLR). Below: Models of the interiors of the icy Galilean satellites (Images: ESA/ATG Medialab). Details on their examination by JUICE are provided by Van Hoolst et al. (2024, this collection) -- pace Sci Rev via PubMed

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Callisto, Europa, Ganymede, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Jupiter, Mapping, Geodesy, Cartography, Bathymetry, Missions & Hardware, Status Report

Characterization of the Surfaces and Near-Surface Atmospheres of Ganymede, Europa and Callisto by JUICE

by Keith CowingSeptember 17, 2024September 17, 2024

We present the state of the art on the study of surfaces and tenuous atmospheres of the icy Galilean satellites Ganymede, Europa and Callisto, from past and ongoing space exploration […]

UV absorption cross sections for the phosphorus species in the network that undergo photolysis reactions. The photolysis threshold wavelength for each species is indicated by the coloured arrows. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Jupiter, Saturn, Status Report, Water/Hycean Worlds & Oceanography

A Photochemical PHO Network For Hydrogen-dominated Exoplanet Atmospheres

by Keith CowingSeptember 13, 2024September 13, 2024

Due to the detection of phosphine PH3 in the Solar System gas giants Jupiter and Saturn, PH3 has long been suggested to be detectable in exosolar substellar atmospheres too. However, […]

Biosignatures & Paleobiology, Europa, Icy Worlds, Jupiter, Missions & Hardware, Press Release

NASA Media Preview Of The Europa Clipper Astrobiology Mission

by Keith CowingSeptember 11, 2024September 11, 2024

NASA will host a news conference at 11 a.m. EDT Tuesday, Sept. 17, at the agency’s Jet Propulsion Laboratory in Southern California to discuss the upcoming Europa Clipper mission to […]

Calibrated images of Ganymede’s 630.0 nm auroral emission displayed in 20 R contours. To better reveal the spatial variability we smoothed the data using a Gaussian kernel with a FWHM of 0. ′′5 approximating typical seeing conditions for the morning of 2021-06-08 UTC. The time in the upper left of each image is the UTC time at the start of the observation, the annotation in the lower right is the distance to the plasma sheet centrifugal equator; positive when Ganymede is above the mid-plane and negative when it is below. As Ganymede moved vertically through the plasma sheet, the hemisphere closest to the mid-plane exhibited the brightest aurora. From approximately 14:00 to 14:45 UTC, Ganymede is within ±0.5 RJ and the brightness is more evenly-distributed across the disk. Ganymede passed through the highestdensity plasma mid-plane at 14:20 UTC, so the top two rows display data when Ganymede was above the mid-plane (with enhanced brightness at southern latitudes) and the bottom row displays data when Ganymede was below the mid-plane (with enhanced brightness at northern latitudes). Because of the blurring effect of atmospheric seeing, the calibrated brightness distribution of the individual pixels is lower than the disk-averaged value reported in de Kleer et al. (2023) and table 1, which assume all emission originates from a disk with Ganymede’s solid-angular size. The white grid shows the physical size and orientation of Ganymede, with north pointing upward (for more details on this observing geometry, see figure 2). -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Ganymede, Icy Worlds, Jupiter, Space Weather & Heliophysics, Status Report, Water/Hycean Worlds & Oceanography

Short-Timescale Spatial Variability of Ganymede’s Optical Aurora

by Keith CowingSeptember 11, 2024September 11, 2024

Ganymede’s aurora are the product of complex interactions between its intrinsic magnetosphere and the surrounding Jovian plasma environment and can be used to derive both atmospheric composition and density.

MAJIS images of the Pacific Ocean -- ESA

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

Astrobiology Mission Update: Juice Confirms That Earth Is Habitable

by Keith CowingSeptember 10, 2024September 10, 2024

During its flyby of Earth on 20 August, ESA’s Jupiter Icy Moons Explorer (Juice) found ingredients for life in Earth’s atmosphere.

Kobe University HIRATA Naoyuki was the first to realize that the location of an asteroid impact on Jupiter’s moon Ganymede is almost precisely on the meridian farthest away from Jupiter. This implied that Ganymede had undergone a reorientation of its rotational axis and allowed Hirata to calculate what kind of impact could have caused this to happen.CREDIT HIRATA Naoyuki

Astrogeology, Comets and Asteroids, Ganymede, Icy Worlds, Impact events, Jupiter, Pluto, Press Release, Water/Hycean Worlds & Oceanography

A Gigantic Asteroid Impact Shifted The Axis Of Ganymede

by Keith CowingSeptember 4, 2024September 4, 2024

Around 4 billion years ago, an asteroid hit the Jupiter moon Ganymede. Now, a Kobe University researcher realized that the Solar System’s biggest moon’s axis has shifted as a result […]

A schematic configuration of PRIDE (not to scale) supporting two Jovian missions, JUICE (the lower left spacecraft) and Europa Clipper (the upper right spacecraft). The spacecraft are in two-way radio contact (blue arrows) with mission-specific Earth-based tracking stations (blue Earthbased antennas). Earth-based VLBI radio telescopes (three magenta Earth-based antennas) receive radio signals from the spacecraft (yellow arrows) and emission of distant natural celestial radio sources (red arrows). The configuration can operate at X- and/or Ka-bands, (8.4 GHz and/or 32 GHz, respectively). -- astro-ph.EP

Europa, Ganymede, Io, Jupiter, Missions & Hardware, Status Report

Planetary Radio Interferometry and Doppler Experiment as an Operational Component of the Jupiter Icy Moons Explorer Mission

by Keith CowingAugust 29, 2024August 28, 2024

We present an overview of the operations and engineering interface for Planetary Radio Interferometry and Doppler Experiment (PRIDE) radio astronomy observations as a scientific component of the ESA s Jupiter […]