Saturn Archives

Astronomy & Telescopes, Exoplanets, -moons, -comets, Impact events, Status Report

Migration of Bodies to the Earth from Different Distances from the Sun

by Keith CowingNovember 20, 2024November 20, 2024

Migration of bodies under the gravitational influence of almost formed planets was studied, and probabilities of their collisions with the Earth and other terrestrial planets were calculated. Based on the […]

Isobaric slices of the expeRT/MITgcm runs at t = 2000 simulation days. The white lines indicate the horizontal wind velocity fields. -- astro-ph.EP

Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Gas Giants, Saturn, Status Report

A Combined 3D Model Applied To Cloudy Warm Saturn Type Exoplanets Around M-dwarfs

by Keith CowingOctober 24, 2024October 24, 2024

Warm Saturn type exoplanets orbiting M-dwarfs are particularly suitable for in-depth cloud characterisation through transmission spectroscopy due to their favourable stellar to planetary radius contrast.

A schematic diagram of the sulfur cycle on the icy Galilean moons. Not all processes operate on all moons and the circles with E, G, and C indicate which processes seem to be more restricted to Europa, Ganymede, and Callisto, respectively. Ice radiolysis happens on all icy surfaces and reactions of radiolytically produced H2SO4 can transform brine salts to sulfates. Only for Europa and Callisto the subsurface ocean is likely to be in contact with the rocky ocean floor but not for Ganymede, where massive dense ice layers prevents ongoing exchange of the subsurface with the silicates. The ocean compositions seem to be all quite similar in the beginning, and Ganymede’s ocean might be the oldest ur-ocean remaining since isolation by dense ice. Subsurface oceans on Europa and Callisto can evolve depending on silicate mantle outgassing into the oceans which may increase salinity over time. On Europa acidification from radiolytically produced H2SO4 may happen, which could lead to an ocean with compositional gradients and pH and development of a halocline. This diagram does not claim completeness and is an attempt to summarize observations, ideas and interpretations. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Enceladus, Europa, Ganymede, Gas Giants, Icy Worlds, Imaging & Spectroscopy, Io, Jupiter, Mapping, Geodesy, Cartography, Bathymetry, Neptune, Saturn, Status Report, Titan, Uranus

Sulfur in the Giant Planets, their Moons, and Extrasolar Gas Giant Planets

by Keith CowingOctober 18, 2024October 18, 2024

We review sulfur chemistry of the gas giant planets and their moons where sulfur compounds are observed. The major S-bearing gas in the upper atmospheres of the giant planets is […]

An illustration showing the trajectory of ESA’s Juice spacecraft during its lunar-Earth gravity assist, featuring a high-resolution ENA image of the million-degree hot plasma halo encircling Earth captured by NASA’s JENI instrument. The white rings denote equatorial distance of 4 and 6 Earth radii. The inset showcases measurements taken by the NASA’s JENI and JoEE instruments during their passage through the radiation belts, revealing a highly structured energetic ion and electron environment. Credit: ESA/NASA/Johns Hopkins APL/Josh Diaz

Gaia - Planetary Perspectives, Jupiter, Magnetic Fields, Electromagnetism, bioelectricity,, Missions & Hardware, Press Release, Radiation, Space Weather & Heliophysics

NASA Instruments On ESA Juice Astrobiology Probe Image Earth’s Radiation Belt

by Keith CowingOctober 2, 2024October 2, 2024

From Aug. 19-20, ESA’s (European Space Agency’s) Juice (Jupiter Icy Moons Explorer) mission made history with a daring lunar-Earth flyby and double gravity assist maneuver, a spaceflight first. As the […]

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 […]

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, […]

Icy Worlds, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Neptune, Pluto, Saturn, Status Report, Triton, Water/Hycean Worlds & Oceanography

Twin Worlds, Divergent Fates: How Obliquity has Differently Shaped Pluto’s and Triton’s Landscapes and Climates

by Keith CowingSeptember 5, 2024September 5, 2024

Triton and Pluto are believed to share a common origin, both forming initially in the Kuiper Belt but Triton being later captured by Neptune. Both objects display similar sizes, densities, […]

Biosignatures & Paleobiology, Cryobiology, Habitable Zones, Icy Worlds, Mimas, Saturn, Status Report, Tethys, Water/Hycean Worlds & Oceanography

The Evolution Of A Young Ocean Within Mimas

by Keith CowingAugust 19, 2024October 7, 2025

The fractured, young surfaces on confirmed ocean worlds such as Europa and Enceladus suggest that ocean-bearing moons with relatively thin overlying ice shells should be easy to identify. Hence, the […]

The surface of Titan as seen by the ESA Huygens lander -- NASA/ESA

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Cryobiology, Exploration Gear & Tech, Icy Worlds, Imaging & Spectroscopy, Saturn, Status Report, Titan

Titan’s Rocks Of Ice – An Interview with Christopher McKay

by Keith CowingJuly 30, 2024July 30, 2024

Huygens sent back only one picture from the surface of Titan. Some people ask, “Are there any more pictures?” They’re used to the Mars rovers, where every day you get […]

Cassini’s antenna is pointed at the predicted specular point where the angle of incidence (θi) equals the angle of reflection (θr), measured from the local vertical. Right circularly polarized (RCP) signals were transmitted, and at least one of the NASA Deep Space Network (DSN) antennas on Earth captured the echo. At the surface of Titan, a left circularly polarized (LCP) component of the echo signal was generated, requiring the presence on the ground of two receiving channels. Complex samples of each receiver output were collected at 16,000 samples/s and stored for later processing. The purpose of this figure is to illustrate the geometry of the observations and distances on the coordinate axes that are not drawn to scale. -- Nature Communications

Astrogeology, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Cryobiology, Exoplanets, -moons, -comets, Icy Worlds, Missions & Hardware, Press Release, Titan, Water/Hycean Worlds & Oceanography

New Analysis Of Cassini Data Yields Insights Into Titan’s Seas

by Keith CowingJuly 29, 2024July 29, 2024

A new study of radar experiment data from the Cassini-Huygens mission to Saturn has yielded fresh insights related to the makeup and activity of the liquid hydrocarbon seas near the […]