Cassini Archives

Enceladus Cassini phase curves from Li et al. (2023), with their corresponding colour filter used in this analysis. The datapoint colours are a crude guide for the different wavelengths of the filters. Some of the filters do not have alternative names. -- astro-ph.EP

Astronomy & Telescopes, Biosignatures & Paleobiology, Enceladus, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Jupiter, Status Report

Enceladus And Jupiter As Exoplanets: The Opposition Surge Effect

by Keith CowingFebruary 21, 2025February 21, 2025

Planets and moons in our Solar System have strongly peaked reflected light phase curves at opposition. In this work, we produce a modified reflected light phase curve model and use […]

Distribution of fluvial and lacustrine features on Titan. Most of Titan’s valley networks, lakes, and seas are concentrated at polar latitudes, though valley networks are comparably more globally distributed (Miller et al. 2021). Alluvial fans are primarily found at Titan’s mid-latitudes (Birch et al. 2016). At both poles, Titan’s largest lakes, seas, and paleoseas concentrate on the eastern hemisphere, while most of the smaller lakes are on the opposite hemisphere (Birch et al. 2017). The largest cluster of small lakes are in Titan’s ‘Lake District’, a region elevated above the seas by 100’s of meters. Major regions and features are labeled, along with approximated locations of the Huygens lander and the Dragonfly landing site at Selk Crater. -- astro-ph.EP

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Cryobiology, Icy Worlds, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Missions & Hardware, Saturn, Status Report, Titan

Titan’s Fluvial and Lacustrine Landscapes

by Keith CowingFebruary 5, 2025February 5, 2025

In this chapter we begin with a review of Titan’s fluvial and lacustrine landscapes as observed with Cassini remote sensing data, and what the many discoveries have revealed about Titan’s […]

Examples of images in the Cassini ISS data set taken with the Narrow Angle Camera (NAC) CLR‐CB3 filters: upper two rows—no clouds. Lower two rows— with clouds. Note varying viewing angles, surface sections, and distances for each capture. Image names as listed in NASA planetary data system (PDS) provided (JPL et al., 2017). -- astro-ph.IM

AI - Data - Apps - Cybernetics, Atmospheres, Climate, Weather, Imaging & Spectroscopy, Status Report, Titan

Rapid Automated Mapping of Clouds on Titan With Instance Segmentation

by Keith CowingJanuary 9, 2025January 9, 2025

Despite widespread adoption of deep learning models to address a variety of computer vision tasks, planetary science has yet to see extensive utilization of such tools to address its unique […]

NASA image of Titan using the Cassini VIMS (visual and infrared mapping spectrometer) instrument. One impact crater is visible near the center. The dark areas near the equator are organic-rich sand dunes, and the dark areas in the north polar region are liquid methane/ethane lakes. White clouds are also visible in the northern hemisphere. -- Credit NASA/ Cassini VIMS

Astrogeology, Biogeochemical Cycles & Geobiology, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Press Release, Saturn, Titan, Water/Hycean Worlds & Oceanography

Titan Has An Insulating Methane-rich Crust Up To Six Miles Thick

by Keith CowingNovember 25, 2024November 25, 2024

Saturn’s largest moon Titan is the only place other than Earth known to have an atmosphere and liquids in the form of rivers, lakes and seas on its surface. Because […]

(A) Schematic of assumptions concerning the outer layers of Enceladus, where H2 (and other solutes) and H2O erupt from the subsurface ocean as a plume of gas. As solutes and H2O vaporize and travel through the tiger stripes, H2O condenses onto the surrounding ice shell as it travels outward, enriching the plume in solutes. Once out of the ice shell conduit, the ratio of solutes to H2O remains the same as the gases expand into the vacuum of space and are detected by Cassini’s INMS. (B) Calculated log aqueous activities (at 273.15 K) of constrained species, resulting from the process illustrated in the left panel using data from Table 1, are displayed as functions of tiger-stripe temperatures. The dashed curve represents a hypothetical organic molecule detected at 1 ppm in the plume gas and then converted into log aqueous activity. -- chemrxiv.org

Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Cryobiology, Enceladus, Europa, Habitable Zones, Icy Worlds, Origin & Evolution of Life, Status Report

Distinguishing Potential Organic Biosignatures on Ocean Worlds from Abiotic Geochemical Products using Thermodynamic Calculations

by Keith CowingNovember 8, 2024November 8, 2024

The search for life in our solar system often involves efforts to detect organic molecules, which have been found on many extraterrestrial bodies, including planets, moons, meteorites, comets, and asteroids. […]

This image is a simulation of how NASA's Europa Clipper will understand which areas of the Jovian moon Europa are warm and active by studying the moon's thermal emissions. larger image

Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Enceladus, Europa, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Simulated View of Thermal Emissions from Europa

by Keith CowingOctober 21, 2024October 21, 2024

Scientists based this image on a model of data from NASA’s Galileo mission and data from an instrument on NASA’s Cassini mission that studied warm regions of Saturn’s moon Enceladus […]

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 […]

Contribution functions at selected wavenumbers calculated for the best-fitting models (Fig. 5) of CIRS (red lines) and TEXES (blue lines) observations. These contribution functions, which have been normalized at each wavenumber, are Jacobians that give the rate of change of spectral flux with temperature (Panel A), logarithm of C2H2 mole fraction (Panel B), and logarithm of C2HD mole fraction (Panel C). -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Imaging & Spectroscopy, Status Report, Titan

The D/H Ratio in Titan’s Acetylene From High Spectral Resolution IRTF/TEXES Observations

by Keith CowingJuly 31, 2024July 31, 2024

We report observations of deuterated acetylene (C2HD) at 19.3 μm (519 cm−1) with the Texas Echelon Cross Echelle Spectrograph on the NASA Infrared Telescope Facility in July 2017.

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 […]