Search Publications
Neptune's rotational period suggested by the extraordinary stability of two features
Karkoschka, Erich
The interior rotation and motions in giant planets have generally been probed only at radio wavelengths from spacecraft near the planet, except for Jupiter's radio emission detectable from Earth. Here I suggest that Neptune's interior can be indirectly probed at visible wavelength by tracking 10 features that are connected with a stationary latitu…
Optical and infrared colors of transneptunian objects observed with HST
Grundy, W. M.; Noll, K. S.; Benecchi, S. D. +2 more
We present optical colors of 72 transneptunian objects (TNOs), and infrared colors of 80 TNOs obtained with the WFPC2 and NICMOS instruments, respectively, on the Hubble Space Telescope (HST). Both optical and infrared colors are available for 32 objects that overlap between the datasets. This dataset adds an especially uniform, consistent and lar…
Photometry of Triton 1992-2004: Surface volatile transport and discovery of a remarkable opposition surge
Buratti, B. J.; Hillier, J. K.; Hicks, M. D. +9 more
Triton, the large satellite of Neptune, was imaged by the Voyager 2 spacecraft in 1989 with dark plumes originating in its volatile-rich south polar region. Southern summer solstice, a time when seasonal volatile transport should be at a maximum, occurred in 2001. Ground-based observations of Triton's rotational light curve obtained from Table Mou…
Evidence of volcanic and glacial activity in Chryse and Acidalia Planitiae, Mars
Mellon, Michael T.; McEwen, Alfred S.; Keszthelyi, Laszlo P. +3 more
Chryse and Acidalia Planitiae show numerous examples of enigmatic landforms previously interpreted to have been influenced by a water/ice-rich geologic history. These landforms include giant polygons bounded by kilometer-scale arcuate troughs, bright pitted mounds, and mesa-like features. To investigate the significance of the last we have analyze…
The near-IR spectrum of Titan modeled with an improved methane line list
Bailey, Jeremy; Meadows, V. S.; Ahlsved, Linda
We have obtained spatially resolved spectra of Titan in the near-infrared J, H and K bands at a resolving power of ∼5000 using the near-infrared integral field spectrometer (NIFS) on the Gemini North 8 m telescope. Using recent data from the Cassini/Huygens mission on the atmospheric composition and surface and aerosol properties, we develop a mul…
Impacts into non-polar ice-rich paleodeposits on Mars: Excess ejecta craters, perched craters and pedestal craters as clues to Amazonian climate history
Head, James W.; Kadish, Seth J.
We compare three previously independently studied crater morphologies - excess ejecta craters, perched craters, and pedestal craters - each of which has been proposed to form from impacts into an ice-rich surface layer. Our analysis identifies the specific similarities and differences between the crater types; the commonalities provide significant…
Post-equinox observations of Uranus: Berg's evolution, vertical structure, and track towards the equator
de Pater, Imke; Sromovsky, L. A.; Fry, P. M. +5 more
We present observations of Uranus taken with the near-infrared camera NIRC2 on the 10-m W.M. Keck II telescope, the Wide Field Planetary Camera 2 (WFPC2) and the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) from July 2007 through November 2009. In this paper we focus on a bright southern feature, referred to as the "Berg." In Sro…
EUV spectroscopy of the Venus dayglow with UVIS on Cassini
Esposito, L. W.; Gérard, J. -C.; Hubert, B. +4 more
We analyze EUV spatially-resolved dayglow spectra obtained at 0.37 nm resolution by the UVIS instrument during the Cassini flyby of Venus on 24 June 1999, a period of high solar activity level. Emissions from OI, OII, NI, CI and CII and CO have been identified and their disc average intensity has been determined. They are generally somewhat bright…
The atmospheric influence, size and possible asteroidal nature of the July 2009 Jupiter impactor
Baines, K. H.; Momary, T. W.; Hueso, R. +24 more
Near-infrared and mid-infrared observations of the site of the 2009 July 19 impact of an unknown object with Jupiter were obtained within days of the event. The observations were used to assess the properties of a particulate debris field, elevated temperatures, and the extent of ammonia gas redistributed from the troposphere into Jupiter's strato…
Decadal variations in a Venus general circulation model
Lebonnois, Sebastien; Schubert, Gerald; Parish, Helen F. +3 more
The Community Atmosphere Model (CAM), a 3-dimensional Earth-based climate model, has been modified to simulate the dynamics of the Venus atmosphere. The most current finite volume version of CAM is used with Earth-related processes removed, parameters appropriate for Venus introduced, and some basic physics approximations adopted. A simplified New…