Search Publications
Cassini RADAR constraint on Titan's winter polar precipitation
Lorenz, R. D.; West, R. D.; Johnson, W. T. K.
The Cassini RADAR instrument made a dedicated cloud backscatter observation near Titan's north pole, presently in winter darkness, to constrain the precipitation of material onto the surface. The detection limit is ∼5 orders of magnitude above that expected in methane rainstorms, and rules out 'drizzle' of more than ∼10cm/yr, placing constraints o…
HST spectral imaging of Titan's haze and methane profile between 0.6 and 1 µm during the 2000 opposition
Young, E. F.; Anderson, C. M.; McKay, C. P. +1 more
We report on the analysis of high spatial resolution visible to near-infrared spectral images of Titan at L=240° in November 2000, obtained with the Space Telescope Imaging Spectrograph instrument on board the Hubble Space Telescope as part of program GO-8580. We employ a radiative transfer fractal particle aerosol model with a Bayesian parameter …
Hydrodynamical and radiative transfer modeling of meteoroid impacts into Saturn's rings
Sugita, Seiji; Cuzzi, Jeffrey N.; Asphaug, Erik +2 more
In a small hypervelocity impact, superheated gas and particles glow brightly with thermal emission for a brief time interval at short wavelengths; this phenomenon is referred to as an impact flash. Over the past decade, impact flashes have been observed on the Moon and in the laboratory in both the IR and visible portions of the spectrum. These ph…
Comment on “Comparison of the composition of the Tempel 1 ejecta to the dust in Comet C/Hale Bopp 1995 O1 and YSO HD 100546” by C.M. Lisse, K.E. Kraemer, J.A. Nuth III, A. Li, D. Joswiak [2007. Icarus 187, 69 86]
Bockelée-Morvan, Dominique; Crovisier, Jacques
Lisse et al. [Lisse, C.M., Kraemer, K.E., Nuth III, J.A., Li, A., Joswiak, D., 2007. Icarus 187, 69-86] recently presented a new analysis of an ISO spectrum of Comet C/1995 O1 (Hale-Bopp), from which they claimed the identification of many new dust species. Among them are PAHs, which were not found in our first analysis of the ISO spectra. We pres…
Release of N 2, CH 4, CO 2, and H 2O from surface ices on Enceladus
Hodyss, Robert; Goguen, Jay D.; Johnson, Paul V. +2 more
We vapor deposit at 20 K a mixture of gases with the specific Enceladus plume composition measured in situ by the Cassini INMS [Waite, J.H., Combi, M.R., Ip, W.H., Cravens, T.E., McNutt, R.L., Kasprzak, W., Yelle, R., Luhmann, J., Niemann, H., Gell, D., Magee, B., Fletcher, G., Lunine, J., Tseng, W.L., 2006. Science 311, 1419-1422] to form a mixed…
Volcanology of Arnus Vallis, Mars
Rampey, Michael L.; Harvey, Ralph P.
Arnus Vallis (AV) is a >300-km-long sinuous, rille located on the northeastern flank of the Syrtis Major volcano on Mars. Observational evidence presented here suggests that AV formed as an open lava channel that was at least partly incised into the pre-existing terrain. The lava source area consists of a sub-circular pit at the southwestern en…
In situ thermal conductivity measurements of Titan's lower atmosphere
Lorenz, R. D.; Hagermann, A.; Leese, M. R. +8 more
Thermal conductivity measurements, presented in this paper (Fig. 3), were made during the descent of the Huygens probe through the atmosphere of Titan below the altitude of 30 km. The measurements are broadly consistent with reference values derived from the composition, pressure and temperature profiles of the atmosphere; except in narrow altitud…
BVR photometry of Hyperion near the time of the 2005 Cassini encounter
Buratti, Bonnie J.; Hicks, Michael D.; Basilier, Erik N.
Six nights of BVR photometry and three nights of R photometry were collected over a month-long period shortly after the Cassini encounter with Hyperion on September 24 2005. Our observations were designed to help constrain the rotational state of the chaotically rotating satellite. Fourier analysis of our lightcurve data yields three possible peri…
The Saturn system's icy satellites: New results from Cassini
Buratti, B. J.; Hendrix, A. R.; Lopes, R. M. C.
Global-scale near infrared variability on Mars: Analysis of 2003 Mars opposition observations from HST/NICMOS
Wolff, M. J.; Noll, K.; Noe Dobrea, E. +3 more
We have used HST/NICMOS to observe approximately 57% of the martian surface in 7 narrow band filters (0.97, 1.08, 1.13, 1.66, 1.90, 2.12, and 2.15 µm) during the 2003 opposition ( L∼250°) and at a resolution of ∼12 km/pixel. Principal components analysis (PCA) of the dataset has identified regional variability on scales of hundreds of kilome…