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Cassini ISS astrometric observations of the inner jovian satellites, Amalthea and Thebe
Porco, C. C.; Spitale, J. N.; Cooper, N. J. +1 more
We present a total of 289 new astrometric observations of the inner jovian satellites, Amalthea and Thebe, obtained using the Cassini ISS narrow angle camera. Observations were made using image sequences from 2000 December 11-12 (inbound) and 2001 January 15-16 (outbound), at phase angles of approximately 2° and 122°, respectively. Target distance…
The first detection of propane on Saturn
Bézard, Bruno; Moses, Julianne I.; Lacy, John H. +3 more
We report the first detection of propane, C 3H 8, in Saturn's stratosphere. Observations taken on September 8, 2002 UT at NASA's IRTF using TEXES, show multiple emission lines due to the 748 cm -1ν band of C 3H 8. Using a line-by-line radiative transfer code, we are able to fit the data by sca…
Interaction of moist convection with zonal jets on Jupiter and Saturn
Ingersoll, Andrew P.; Li, Liming; Huang, Xianglei
Observations suggest that moist convection plays an important role in the large-scale dynamics of Jupiter's and Saturn's atmospheres. Here we use a reduced-gravity quasigeostrophic model, with a parameterization of moist convection that is based on observations, to study the interaction between moist convection and zonal jets on Jupiter and Saturn…
Jupiter's White Oval turns red
Simon-Miller, Amy A.; Karkoschka, Erich; Chanover, Nancy J. +3 more
Jupiter's remaining White Oval changed color in late 2005 and became noticeably red in early 2006, as reported by amateur observers. We present wind and color analyses from high spatial resolution images taken with the Hubble Space Telescope Advanced Camera for Surveys in April 2006. These images suggest that the recent color change was tied to a …
A model of the ionosphere of Saturn's rings and its implications
Luhmann, J. G.; Tokar, R. L.; Johnson, R. E. +2 more
The detection of cold O2+ and O + ions in the vicinity of Saturn's rings during the Cassini Orbiter orbit insertion confirmed expectations that the rings would have a water product atmosphere and ionosphere. These observations prompted a new look at their origin and nature by Johnson et al. [Johnson, R.E., Luhmann, J.G., Tokar, R.L., Bo…
First ENA observations at Mars: Solar-wind ENAs on the nightside
Coates, A. J.; Kallio, E.; Fedorov, A. +44 more
We present measurements with an Energetic Neutral Atom (ENA) imager on board Mars Express when the spacecraft moves into Mars eclipse. Solar wind ions charge exchange with the extended Mars exosphere to produce ENAs that can spread into the eclipse of Mars due to the ions' thermal spread. Our measurements show a lingering signal from the Sun direc…
Energetic Neutral Atoms (ENA) at Mars: Properties of the hydrogen atoms produced upstream of the martian bow shock and implications for ENA sounding technique around non-magnetized planets
Coates, A. J.; Kallio, E.; Fedorov, A. +43 more
We have studied the interaction of fast solar wind hydrogen atoms with the martian atmosphere by a three-dimensional Monte Carlo simulation. These energetic neutral hydrogen atoms, H-ENAs, are formed upstream of the martian bow shock. Both H-ENAs scattered and non-scattered from the martian atmosphere/exosphere were studied. The colliding H-ENAs w…
Solar wind plasma protrusion into the martian magnetosphere: ASPERA-3 observations
Coates, A. J.; Kallio, E.; Fedorov, A. +37 more
The ASPERA-3 experiment onboard the Mars Express spacecraft revealed, near the wake boundary of Mars, a spatially narrow, strip-like plasma structure composed of magnetosheath-like electrons and planetary ions. The peak electron energy often exceeds the peak energy at the bow shock that indicates a significant heating (acceleration) during the str…
Martian phase function: Modeling the visible to near-infrared surface photometric function using HST-WFPC2 data
Soderblom, Jason M.; Bell, James F.; Wolff, Michael J. +1 more
Images of Mars in the visible to near-infrared acquired from 1996 to 2005 using the Hubble Space Telescope WFPC2 have been used to model the martian surface photometric function at 502, 673, 953, and 1042 nm. These data range in spatial resolution from 12 to 70 km/pixel at the sub-Earth point, and in phase angle coverage from 0.34° to 40.5°. The W…
Physical properties of Titan's surface at the Huygens landing site from the Surface Science Package Acoustic Properties sensor (API-S)
Lorenz, R. D.; Hagermann, A.; Leese, M. R. +6 more
We present the results from the first sonar to be deployed outside of Earth, and the first active acoustic instrument on Titan, onboard the Huygens probe, and the implications of its data for the geomorphology and characteristics of the Huygens landing site. Signals were recorded from 90 m downwards until impact, with a maximum sensor footprint di…