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Observations and Modeling of the Opposition Surges of the Icy Moons of Saturn Based on Cassini Visual Infrared Mapping Spectrometer Data
Buratti, B. J.; Hendrix, A. R.; Dalba, P. A. +5 more
Observations of the opposition surges on the main moons of Saturn (Mimas, Enceladus, Tethys, Dione, Rhea, and Iapetus) during Cassini's prime and extended missions are reduced and analyzed. The main data set comes from the Visual Infrared Mapping Spectrometer (VIMS) with wavelength coverage in the visible and near-infrared out to 3.60 µm, co…
Local-time Dependence of Chemical Species in the Venusian Mesosphere
Shao, Wencheng D.; Zhang, Xi; Mendonça, João +1 more
Observed chemical species in the Venusian mesosphere show local-time variabilities. SO2 at the cloud top exhibits two local maxima over local time, H2O at the cloud top is uniformly distributed, and CO in the upper atmosphere shows a statistical difference between the two terminators. In this study, we investigated these loca…
Titan Stratospheric Haze Bands Observed in Cassini VIMS as Tracers of Meridional Circulation
Le Mouélic, S.; Rodriguez, S.; Sotin, C. +9 more
We analyzed Cassini data to derive the nature and evolution of circumglobal annuli observed in the stratosphere of Titan, Saturn's largest moon. The annuli were observed between 2004 and 2017 in data acquired by the Visual and Infrared Mapping Spectrometer on board the Cassini spacecraft. We observed a north polar annulus, an equatorial annulus, a…
Uranus's and Neptune's Stratospheric Water Abundance and Vertical Profile from Herschel-HIFI
Irwin, P. G. J.; Teanby, N. A.; Nixon, C. A. +2 more
Here we present new constraints on Uranus's and Neptune's externally sourced stratospheric water abundance using disk-averaged observations of the 557 GHz emission line from Herschel's Heterodyne Instrument for the Far-Infrared. Derived stratospheric column water abundances are × 1014 cm‑2 for Uranus and ×1014 cm
Planet Four: Derived South Polar Martian Winds Interpreted Using Mesoscale Modeling
Schwamb, Megan E.; Michaels, Timothy I.; Lintott, Chris J. +3 more
For the first time, model-derived and imagery-derived wind directions and speeds have been compared in Mars's south polar region. Seasonal fan-shaped deposits are routinely observed by HiRISE in the polar regions. They are widely accepted to result from CO2 gas jet eruptions. Fan lengths, sizes, and shapes can provide information about …
Physical Characterization of 2015 JD1: A Possibly Inhomogeneous Near-Earth Asteroid
Granvik, Mikael; Gustafsson, Annika; Chandler, Colin Orion +7 more
The surfaces of airless bodies such as asteroids are exposed to many phenomena that can alter their physical properties. Bennu, the target of the OSIRIS-REx mission, has demonstrated how complex the surface of a small body can be. In 2019 November, the potentially hazardous asteroid 2015 JD1 experienced a close approach of 0.033 1 au fr…
Spectroscopic Mapping of Io's Surface with HST/STIS: SO2 Frost, Sulfur Allotropes, and Large-scale Compositional Patterns
Brown, Michael E.; Trumbo, Samantha K.; Davis, M. Ryleigh +1 more
Io's intense volcanic activity results in one of the most colorful surfaces in the solar system. Ultraviolet and visible-wavelength observations of Io are critical to uncovering the chemistry behind its volcanic hues. Here, we present global, spatially resolved ultraviolet-visible spectra of Io from the Space Telescope Imaging Spectrograph on the …
Near-infrared Spectroscopy of the Nucleus of Low-activity Comet P/2016 BA14 during Its 2016 Close Approach
Kareta, Theodore; Harris, Walter M.; Reddy, Vishnu +1 more
The near-Earth comet P/2016 BA14 (PanSTARRS) is a slow-rotating, nearly dormant object, a likely dynamical twin of 252P/LINEAR, and was recently shown to have a mid-infrared spectrum very dissimilar to other comets. Comet BA14 was also recently selected as one of the backup targets for the ESA's Comet Interceptor, so a cleare…
Ultraviolet Spectroscopy of Lucy Mission Targets with the Hubble Space Telescope
Emery, Joshua P.; Grundy, Will M.; Humes, Oriel A. +1 more
The recently launched Lucy mission aims to understand the dynamical history of the solar system by examining the Jupiter Trojans, a population of primitive asteroids co-orbital with Jupiter. Using the G280 grism on the Hubble Space Telescope's Wide Field Camera 3, we obtained near-ultraviolet spectra of four of the five Lucy mission targets-(617) …
Identifying Shadowing Signatures of C Ring Ringlets and Plateaus in Cassini Data from Saturn's Ionosphere
Vigren, Erik; Wahlund, Jan-Erik; Dreyer, Joshua +5 more
For orbits 288 and 292 of Cassini's Grand Finale, clear dips (sharp and narrow decreases) are visible in the ${{\rm{H}}}_{2}^{+}$ densities measured by the Ion and Neutral Mass Spectrometer (INMS). In 2017, the southern hemisphere of Saturn was shadowed by its rings and the substructures within. Tracing a path of the solar photons through the ring…