Search Publications
A large cloud outburst at Titan's south pole
Brown, Michael E.; Bouchez, Antonin H.; Roe, Henry G. +1 more
Images of Titan acquired over five nights in October 2004 using the adaptive optics system at the Keck Observatory show dramatic increases in tropospheric cloud activity at the south pole compared with all other images of Titan clouds to date. During this time, Titan's south polar clouds brightened to more than 18 times their typical values. The C…
Structure of the martian wake
Coates, A. J.; Kallio, E.; Fedorov, A. +42 more
We present the first results from the ion mass analyzer IMA of the ASPERA-3 instrument on-board of Mars Express. More than 200 orbits for May 2004-September 2004 time interval have been selected for the statistical study of the distribution of the atmospheric origin ions in the planetary wake. This study shows that the martian magnetotail consists…
Compositional and physical results for Rosetta's new target Comet 67P/Churyumov Gerasimenko from narrowband photometry and imaging
Schleicher, David G.
We present compositional and physical results of Comet 67P/Churyumov-Gerasimenko, the new target of ESA's Rosetta mission. A total of 16 nights of narrowband photometry were obtained at Lowell Observatory during the 1982/83 and 1995/96 apparitions, along with one night of imaging near perihelion in 1996. These data encompass an interval of -61 to …
Reflectance spectra and chemical structure of Titan's tholins: Application to the analysis of Cassini Huygens observations
Quirico, E.; Schmitt, B.; Coll, P. +7 more
Titan's tholins are used as analogs of Titan's aerosols and N-rich organic solids present on many icy surfaces. However, it is not clear whether or not they are relevant analogs, and which kind of tholins should be used among a wide set available in literature. This paper presents reflectance spectral data of two tholins selected as end-members of…
Cassini RADAR observations of Enceladus, Tethys, Dione, Rhea, Iapetus, Hyperion, and Phoebe
Black, Gregory J.; Lorenz, Ralph D.; Hensley, Scott +17 more
Cassini 2.2-cm radar and radiometric observations of seven of Saturn's icy satellites yield properties that apparently are dominated by subsurface volume scattering and are similar to those of the icy Galilean satellites. Average radar albedos decrease in the order Enceladus/Tethys, Hyperion, Rhea, Dione, Iapetus, and Phoebe. This sequence most li…
Debris-covered piedmont glaciers along the northwest flank of the Olympus Mons scarp: Evidence for low-latitude ice accumulation during the Late Amazonian of Mars
Head, James W.; Marchant, David R.; Milkovich, Sarah M.
We use Viking and new MGS and Odyssey data to characterize the lobate deposits superimposed on aureole deposits along the west and northwest flanks of Olympus Mons, Mars. These features have previously been interpreted variously as landslide, pyroclastic, lava flow or glacial features on the basis of Viking images. The advent of multiple high-reso…
Dissipation of Titan's south polar clouds
Brown, Michael E.; Trujillo, Chadwick A.; Bouchez, Antonin H. +2 more
Nearly all adaptive optics images of Titan taken between December 2001 and November 2004 showed tropospheric clouds located within 30° of the south pole. We report here on a dissipation of Titan's south polar clouds observed in twenty-nine Keck and Gemini images taken between December 2004 and April 2005. The near complete lack of south polar clou…
Detection of sporadic impact flashes on the Moon: Implications for the luminous efficiency of hypervelocity impacts and derived terrestrial impact rates
Pallé, E.; Aceituno, J.; Ortiz, J. L. +8 more
We present the first redundant detection of sporadic impact flashes on the Moon from a systematic survey performed between 2001 and 2004. Our wide-field lunar monitoring allows us to estimate the impact rate of large meteoroids on the Moon as a function of the luminous energy received on Earth. It also shows that some historical well-documented my…
Ultraviolet radiation constraints around the circumstellar habitable zones
Buccino, Andrea P.; Lemarchand, Guillermo A.; Mauas, Pablo J. D.
Ultraviolet radiation is known to inhibit photosynthesis, induce DNA destruction and cause damage to a wide variety of proteins and lipids. In particular, UV radiation between 200 and 300 nm becomes energetically very damaging to most of the terrestrial biological systems. On the other hand, UV radiation is usually considered one of the most impor…
A global circulation model of Saturn's thermosphere
Yelle, R. V.; Müller-Wodarg, I. C. F.; Aylward, A. D. +1 more
We present the first 3-dimensional self-consistent calculations of the response of Saturn's global thermosphere to different sources of external heating, giving local time and latitudinal changes of temperatures, winds and composition at equinox and solstice. Our calculations confirm the well-known finding that solar EUV heating alone is insuffici…