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ISO Observations of Mars: An Estimate of the Water Vapor Vertical Distribution and the Surface Emissivity
de Graauw, Th.; Forget, F.; Lellouch, E. +9 more
Infrared spectra of Mars were taken with the two complementary spectrometers onboard the European Space Agency's Infrared Space Observatory (ISO), in both moderate- and high-resolution mode. From the strengths of the observed water lines we derived information about the vertical distribution of water vapor and on the emissivity of the dust/surface…
NOTE: Ground-Based Observations of Cloud Features on Uranus
Baines, K. H.; Sromovsky, L. A.; Fry, P. M. +1 more
NSFCAM observations at 1.7 µm in 1998 and 1999 recorded the first discrete cloud features to appear in ground-based digital images of Uranus and the brightest such feature ever observed. The differential contributions of these northern hemisphere features to Uranus' disk-integrated brightness range from 0.8±0.2% and 0.11±0.3% for two 1998 fe…
Mapping Jupiter's Latitudinal Bands and Great Red Spot Using HST/WFPC2 Far-Ultraviolet Imaging
West, Robert A.; Ballester, Gilda E.; Crisp, David +16 more
Jupiter's low and mid-latitudes are examined using ultraviolet (UV) images obtained with the Hubble Space Telescope Wide Field and Planetary Camera 2 over the period of 1994-1997. Effective atmospheric pressures probed by the F160W, F218W, and F255W are estimated at 100, 165, and 370 mbar, respectively, at low latitudes. Far-ultraviolet images of …
A New Observational Search for Vulcanoids in SOHO/LASCO Coronagraph Images
Parker, Joel Wm.; Stern, S. Alan; Levison, Harold F. +3 more
We examined SOHO/LASCO (Solar and Heliospheric Observatory/Large Angle Spectroscopic Coronagraph) C3 coronagraph images to search for the long-suspected population of small bodies, the vulcanoids, in heliocentric orbits interior to Mercury. We searched the entire vulcanoid region from 0.07-0.21 AU by visually blinking daily image averages co-regis…
Long-Lived Vortices and Profile Changes in the 23.7°N High-Speed Jovian Jet
Sánchez-Lavega, A.; García-Melendo, E.; Colas, F. +4 more
This paper addresses the question of up to what extent there are changes in the jovian jets as seen at cloud level and how they relate to the cloud morphology changes. We focus on the particularly interesting region at 24°N where the most intense jovian jet as observed at visual wavelengths resides. The studied period goes from 1991 to 1998, and t…
The Crossings of Saturn Ring Plane by the Earth in 1995: Ring Thickness
Sicardy, Bruno; Dumas, Christophe; Poulet, François +2 more
The crossings of Saturn's ring plane by Earth were observed in the near infrared on May 22 and August 10, 1995, from the 2.2-m telescope of the University of Hawaii, the 2-m telescope at Pic du Midi, France, and with the Adonis adaptive optics camera at the 3.6-m telescope of the European Southern Observatory in Chile. Images from the Hubble Space…
Ballistic Reconstruction of HST Observations of Ejecta Motion Following Shoemaker-Levy 9 Impacts into Jupiter
Ballester, Gilda E.; Clarke, John T.; Hammel, Heidi B. +1 more
We present a detailed analysis of Hubble Space Telescope (HST) Wide Field and Planetary Camera 2 (WFPC 2) images of the first 25 min of the impacts of Comet Shoemaker-Levy 9 fragments A and G with Jupiter and the post impact ejecta patterns observed 1-2 h after each impact event, with a brief analysis of the available observations of the first 25 …
ISO LWS Observations of Mars—Detection of Rotational Modulation in the Far Infrared
de Graauw, Th.; Lellouch, E.; Burgdorf, M. +7 more
A series of far infrared (FIR) spectra of Mars between 43 and 196 µm was taken with the Long Wavelength Spectrometer (LWS) on board the European Space Agency's Infrared Space Observatory (ISO). Analysis of these medium-resolution data reveals a rotational modulation of the disk-averaged FIR brightness temperature. The observed variability of…
Adaptive Optics Observations of Saturn's Ring Plane Crossing in August 1995
Owen, T.; Brahic, A.; Dumas, C. +4 more
Adaptive optics (0.15″ resolution) infrared images of the rings and satellites of Saturn were obtained in August 1995 as the Earth was crossing the ring plane. Twelve clumps were detected in the F ring, including HST S5 and S7 objects. For the first time H magnitudes were obtained for Prometheus, Pandora, Telesto, and Calypso, and J magnitudes for…
Comet Shoemaker-Levy 9 Dust Size and Velocity Distributions
Hahn, Joseph M.; Rettig, Terrence W.
Pre-impact observations of Comet Shoemaker-Levy 9 (S-L9) obtained with the Hubble Space Telescope are examined, and a model of an active, dust-producing comet is fitted to images of fragments G, H, K, and L. The model assumes steady isotropic dust emission from each fragment's sunlit hemisphere. Best-fit results indicate that the dominant light-sc…