Search Publications
The escape of heavy atoms from the ionosphere of HD209458b. II. Interpretation of the observations
Yelle, R. V.; Lavvas, P.; Koskinen, T. T. +1 more
Transits in the H I 1216 Å (Lyman α), O I 1334 Å, C II 1335 Å, and Si III 1206.5 Å lines constrain the properties of the upper atmosphere of HD209458b. In addition to probing the temperature and density profiles in the thermosphere, they have implications for the properties of the lower atmosphere. Fits to the observations with a simple empirical …
Dynamics of Saturn’s great storm of 2010-2011 from Cassini ISS and RPWS
West, Robert A.; Porco, Carolyn C.; Dyudina, Ulyana A. +6 more
Saturn’s quasi-periodic planet-encircling storms are the largest convecting cumulus outbursts in the Solar System. The last eruption was in 1990 (Sánchez-Lavega, A. [1994]. Chaos 4, 341-353). A new eruption started in December 2010 and presented the first-ever opportunity to observe such episodic storms from a spacecraft in orbit around Saturn (Fi…
Crater-based dating of geological units on Mars: Methods and application for the new global geological map
Tanaka, Kenneth L.; Platz, Thomas; Michael, Gregory +2 more
The new, post-Viking generation of Mars orbital imaging and topographical data provide significant higher-resolution details of surface morphologies, which induced a new effort to photo-geologically map the surface of Mars at 1:20,000,000 scale. Although from unit superposition relations a relative stratigraphical framework can be compiled, it was…
Reflectance spectra diversity of silica-rich materials: Sensitivity to environment and implications for detections on Mars
Bell, J. F.; Rice, M. S.; Horgan, B. H. +7 more
Hydrated silica-rich materials have recently been discovered on the surface of Mars by the Mars Exploration Rover (MER) Spirit, the Mars Reconnaissance Orbiter (MRO) Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), and the Mars Express Observatoire pour la Minéralogie, l’Eau, les Glaces, et l’Activité (OMEGA) in several locations. Hav…
One Moon, Many Measurements 3: Spectral reflectance
Yokota, Y.; Mall, U.; Besse, S. +9 more
Remote-sensing datasets obtained by each instrument aboard Selenological and Engineering Explorer (SELENE) and Chandrayaan-1 have not been compared directly, and the characteristics of each instrument’s data, which may reflect the observation conditions of each instrument and/or residual error in instrument calibration, are unknown. This paper des…
The thermal structure of Titan’s upper atmosphere, I: Temperature profiles from Cassini INMS observations
Wahlund, J. -E.; Edberg, N. J. T.; Ågren, K. +3 more
We derive vertical temperature profiles from Ion Neutral Mass Spectrometer (INMS) N2 density measurements from 32 Cassini passes. We find that the average temperature of Titan’s thermosphere varies significantly from pass-to-pass between 112 and 175 K. The temperatures from individual temperature profiles also varies considerably, with …
The temperature and width of an active fissure on Enceladus measured with Cassini VIMS during the 14 April 2012 South Pole flyover
Hedman, Matthew M.; Sotin, Christophe; Baines, Kevin H. +10 more
The width and temperature of the active fissures on Saturn’s satellite Enceladus provide key observable constraints on physical models of these geyser-like eruptions. We analyze a sequence of high spatial resolution near-infrared spectra acquired with VIMS at 0.025 s intervals during a 74 km altitude flyover of the South Pole of Enceladus by the C…
A global topographic map of Titan
Barnes, Jason W.; Stiles, Bryan W.; Kirk, Randolph L. +8 more
Cassini RADAR SARtopo and altimetry data are used to construct a global gridded 1 × 1° elevation map, for use in Global Circulation Models, hydrological models and correlative studies. The data are sparse, and so most of the map domain (∼90%) is populated with interpolated values using a spline algorithm. The highest (∼+520 m) gridded point observ…
An observational study of the response of the upper atmosphere of Mars to lower atmospheric dust storms
Withers, Paul; Pratt, R.
The effects of dust storms on densities, temperatures, and winds in the lower atmosphere of Mars are substantial. Here we use upper atmospheric observations to investigate how dust storms affect the upper atmosphere of Mars. We use aerobraking accelerometer, ultraviolet stellar occultation, and radio occultation datasets to examine the magnitudes …
Stratospheric aerosols on Jupiter from Cassini observations
Zhang, X.; West, R. A.; Banfield, D. +1 more
We retrieved global distributions and optical properties of stratospheric aerosols on Jupiter from ground-based NIR spectra and multiple-phase-angle images from Cassini Imaging Science Subsystem (ISS). A high-latitude haze layer is located at ∼10-20 mbar, higher than in the middle and low latitudes (∼50 mbar). Compact sub-micron particles are main…