Search Publications

Titan's North-South Haze Asymmetry Ratio and Boundary at Visible Wavelengths over the Cassini Mission

Barnes, Jason W.; Lorenz, Ralph D.; Vashist, Aadvik S. +2 more

We document the evolution of the north-south asymmetry (NSA) of Titan's haze albedo during the Cassini mission between 2004 and 2017. We analyze coadded cube images taken at 96 distinct wavelengths between 0.35 and 1.05 µm by the Cassini Visual and Infrared Mapping Spectrometer (VIMS-V) instrument from 14 Titan flybys. Over half of a Titan y…

New Insights into Aristarchus Crater with LRO LAMP Far-ultraviolet Observations

Hendrix, Amanda; Retherford, Kurt; Grava, Cesare +8 more

Aristarchus crater is a Copernican-age impact crater well known for its high-albedo ejecta blanket and nearby flow features rich in pyroclastic materials. The Lyman Alpha Mapping Project (LAMP) is a far-ultraviolet (FUV) spectrograph (57-197 nm) on board the Lunar Reconnaissance Orbiter (LRO). LAMP data identified Aristarchus crater as having a hi…

Erratum: "Temporal Evolution of Titan's Stratospheric Temperatures and Trace Gases from a Two-dimensional Retrieval of Cassini Composite Infrared Spectrometer Data" (2023, PSJ, 4, 140)

Achterberg, Richard K.

Accurate Machine-learning Atmospheric Retrieval via a Neural-network Surrogate Model for Radiative Transfer

Arney, Giada N.; Domagal-Goldman, Shawn D.; Harrington, Joseph +8 more

Atmospheric retrieval determines the properties of an atmosphere based on its measured spectrum. The low signal-to-noise ratios of exoplanet observations require a Bayesian approach to determine posterior probability distributions of each model parameter, given observed spectra. This inference is computationally expensive, as it requires many exec…

A New UV Spectral Feature on Europa: Confirmation of NaCl in Leading-hemisphere Chaos Terrain

Alday, Juan; Roth, Lorenz; Brown, Michael E. +6 more

Recent visible-wavelength observations of Europa's surface obtained with the Hubble Space Telescope (HST) revealed the presence of an absorption feature near 450 nm that appears spatially correlated with leading-hemisphere chaos terrain. This feature was interpreted to reflect the presence of irradiated sodium chloride ultimately sourced from the …

A Survey of CO, CO₂, and H₂O in Comets and Centaurs

Bauer, James; Harrington Pinto, Olga; Womack, Maria +1 more

CO and CO₂ are the two dominant carbon-bearing molecules in comae and have major roles in driving activity. Their relative abundances also provide strong observational constraints to models of solar system formation and evolution but have never been studied together in a large sample of comets. We carefully compiled and analyzed publish…

Photometric Observations of the Binary Near-Earth Asteroid (65803) Didymos in 2015-2021 Prior to DART Impact

Carry, B.; Souami, D.; Dotto, E. +24 more

We performed photometric observations of the binary near-Earth asteroid (65803) Didymos in support of the Double Asteroid Redirection Test (DART) mission that will test the Kinetic Impactor technology for diverting dangerous asteroids. It will hit the Didymos secondary, called Dimorphos, on 2022 September 26. We observed Didymos with 11 telescopes…

International Asteroid Warning Network Timing Campaign: 2019 XS

Popescu, Marcel; Granvik, Mikael; Chambers, Kenneth C. +69 more

As part of the International Asteroid Warning Network's observational exercises, we conducted a campaign to observe near-Earth asteroid 2019 XS around its close approach to Earth on 2021 November 9. The goal of the campaign was to characterize errors in the observation times reported to the Minor Planet Center, which become an increasingly importa…

Thermal Properties of 1847 WISE-observed Asteroids

Masiero, Joseph R.; Tholen, David J.; Hung, Denise +1 more

We present new thermophysical model fits of 1847 asteroids, deriving thermal inertia, diameter, and Bond and visible geometric albedo. We use thermal flux measurements obtained by the Wide-field Infrared Survey Explorer (WISE) during its fully cryogenic phase, when both the 12 µm (W3) and 22 µm (W4) bands were available. We take shape …

An Open-source Bayesian Atmospheric Radiative Transfer (BART) Code. III. Initialization, Atmospheric Profile Generator, Post-processing Routines

Cubillos, Patricio E.; Blecic, Jasmina; Challener, Ryan C. +12 more

This and companion papers by Harrington et al. and Cubillos et al. describe an open-source retrieval framework, Bayesian Atmospheric Radiative Transfer (BART), available to the community under the reproducible-research license via https://github.com/exosports/BART. BART is a radiative transfer code (transit; https://github.com/exosports/transit; R…