Cassini Archives

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 […]

This enhanced color view of Saturn's moon Enceladus shows the south polar terrain, where jets of material spray out form long cracks called Tiger Stripes. Image credit: NASA/JPL-Caltech/Space Science Institute

Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Enceladus, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Missions & Hardware, Status Report

Sub-Micrometer Particles Remote Detection in Enceladus Plume Based on Cassinni’s UV Spectrograph Data

by Keith CowingJuly 20, 2024July 7, 2024

Enceladus is the Saturnian satellite known to have water vapor erupting from its south pole region called Tiger Stripes.

An artist’s rendition of Saturn’s moon Enceladus depicts hydrothermal activity on the seafloor and cracks in the moon’s icy crust that allow material from the watery interior to be ejected into space. New research shows that instruments destined for the next missions could find traces of a single cell in a single ice grain contained in a plume. NASA/JPL-Caltech

Analog Studies, Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Comets and Asteroids, Enceladus, Europa, Extremeophiles and Extreme Environments, Icy Worlds, Imaging & Spectroscopy, Meteorites & Asteroids, Missions & Hardware, Status Report, Water/Hycean Worlds & Oceanography

Laboratory Characterization Of Hydrothermally Processed Oligopeptides In Ice Grains Emitted By Enceladus And Europa

by Keith CowingJune 25, 2024June 25, 2024

The Cassini mission provided evidence for a global subsurface ocean and ongoing hydrothermal activity on Enceladus, based on results from Cassini’s mass spectrometers. Laboratory simulations of hydrothermal conditions on icy […]

Astrogeology, Atmospheres, Climate, Weather, Icy Worlds, Imaging & Spectroscopy, Press Release, Titan, Water/Hycean Worlds & Oceanography

Titan’s Lakes May Be Shaped By Waves

by Keith CowingJune 20, 2024

Titan, Saturn’s largest moon, is the only other planetary body in the solar system that currently hosts active rivers, lakes, and seas. These otherworldly river systems are thought to be […]

Jupiter moon Io, imaged by SHARK-VIS on Jan. 10, 2024. This is the highest resolution image of Io ever obtained by an Earth-based telescope. The image combines three spectral bands — infrared, red and yellow — to highlight the reddish ring around the volcano Pele (below and to the right of the moon's center) and the white ring around Pillan Patera, to the right of Pele.

Astrogeology, Astronomy & Telescopes, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Io, Lava / magma ocean / Volcanic Worlds, Mapping, Geodesy, Cartography, Bathymetry, Press Release

New Telescope Images Of Volcano World Io

by Keith CowingJune 7, 2024June 7, 2024

New images of Jupiter’s volcano-studded moon Io, taken by the Large Binocular Telescope on Mount Graham in Arizona, offer the highest resolution of Io ever achieved with an Earth-based instrument. […]

Left: Map of the plume’s brightness at 2.70 µm derived from an average of five VIMS cubes (V1511798376, V1511800181, V1511800741, V1511801493, and V1511802247). Note that this brightness is mostly due to reflected sunlight from Enceladus’ lit limb and the plume particles. The image is re-projected on a grid with 19 kilometers per pixel and oriented so that the plume points downward. Right: Map of the water-vapor column density derived from the same averaged image. Column densities were calculated using the average residual values and Equation 1. Note that regions of high column density are visible outside the region where the plume particles are bright, which provides evidence that this signal traces a different plume component. The red circles outline Enceladus and the red rectangles show the pixels used for the spectral analysis -- astro-ph.EP

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Enceladus, Icy Worlds, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Constraining Time Variations in Enceladus’ Water-Vapor Plume With Near-Infrared Spectra from Cassini-VIMS

by Keith CowingMay 14, 2024May 14, 2024

Water vapor produces a series of diagnostic emission lines in the near infrared between 2.60 and 2.75 microns. The Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft detected […]

Integrated emission (or ‘moment 0’) maps of Titan’s CH3D (A), CH3CN (B), and continuum (C) spectra. Panels (A) and (B) correspond to the emission integrated over the spectral transitions shown in Fig. 1. The synthesized ALMA beam size (FWHM of the ALMA PSF) is shown as the hatched ellipse in the lower left; Titan’s solid surface, latitude and longitudes are shown (solid and dashed blue lines). Contours are in increments of 1σ (A) and 10σ (B). Spectra were extracted for radiative transfer modeling at 20◦ latitude bins as displayed on the continuum emission map in panel C (yellow squares), and the corresponding area representing the ALMA beam foot-print used to generate synthetic spectra from these individual regions on Titan’s limb are shown (yellow ellipses). Altitudes of 150 km and 1200 km above Titan’s surface are denoted by dotted and dashed blue circles, respectively, on the continuum map. -- astro-ph.EP

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Habitable Zones, Imaging & Spectroscopy, Status Report, Titan

Observations of Titan’s Stratosphere During Northern Summer: Temperatures, CH3CN and CH3D Abundances

by Keith CowingMay 7, 2024May 7, 2024

Titan’s atmospheric composition and dynamical state have previously been studied over numerous epochs by both ground- and space-based facilities.

Contour plot of temperatures from the atmospheric structure model, using CIRS observations from 2015 and 2017 at pressures higher than 10−6 bar to 3 × 10−4 bar and UVIS observations at pressures lower than 10−6 to 2 × 10−8 bar, where the quoted pressure limits depend on latitude. The temperatures in the coverage gap between the instruments were filled in to match the H2 density vs. radius in the thermosphere. The black diamonds show the location of the CH4 homopause, taken where CH4 volume mixing ratio equals 5 × 10−5 . A cartoon illustrating speculated low-latitude upwelling is depicted with dashed arrows near the high-altitude homopause levels. astro-ph.EP

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Imaging & Spectroscopy, Missions & Hardware, Saturn, Status Report

A Pole-to-Pole Map Of Hydrocarbons In Saturn’s Upper Stratosphere And Mesosphere

by Keith CowingMay 6, 2024May 6, 2024

We analyze data from the final two years of the Cassini mission to retrieve the distributions of methane, ethane, acetylene, ethylene, and benzene in Saturn’s upper stratosphere and mesosphere from […]

Possible relationship between strike-slip motion and jet activity at Enceladus. Lateral extension along transtensional "pull-apart zones" allows water to rise and feed material to cryovolcanic jets. Credit: James Tuttle Keane

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Enceladus, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Press Release, Water/Hycean Worlds & Oceanography

Water Plumes On Enceladus Caused By Strike–Slip Motion

by Keith CowingMay 1, 2024May 1, 2024

Over the course of its elliptical orbit, the moon Enceladus is squeezed unevenly by Saturn’s gravitational pull and deforms from a spherical shape into a football shape and back again. […]

Cassini

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

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

Sub-Micrometer Particles Remote Detection in Enceladus Plume Based on Cassinni’s UV Spectrograph Data

Laboratory Characterization Of Hydrothermally Processed Oligopeptides In Ice Grains Emitted By Enceladus And Europa

Titan’s Lakes May Be Shaped By Waves

New Telescope Images Of Volcano World Io

Constraining Time Variations in Enceladus’ Water-Vapor Plume With Near-Infrared Spectra from Cassini-VIMS

Observations of Titan’s Stratosphere During Northern Summer: Temperatures, CH3CN and CH3D Abundances

A Pole-to-Pole Map Of Hydrocarbons In Saturn’s Upper Stratosphere And Mesosphere

Water Plumes On Enceladus Caused By Strike–Slip Motion

Tricorder Tech: New Handheld Device Maps Chemical Composition Using Infrared Light

No Statistically Significant Evidence For A Correlation Between Stellar And planetary Composition

Water Planet Recon: How Accurately Can We Measure Earth Ocean’s Deepest Point?

Webb Reveals A Stunning Panorama Of Star Formation

Deep Learning of SHERLOC Raman Spectra For Facilitating Mars Astromaterial Identification