HST Far-Ultraviolet Imaging of Jupiter During the Impacts of Comet Shoemaker-Levy 9

Abstract

Hubble Space Telescope far-ultraviolet images of Jupiter during the Shoemaker-Levy 9 impacts show the impact regions darkening over the 2 to 3 hours after the impact, becoming darker and more extended than at longer wavelengths, which indicates that ultraviolet-absorbing gases or aerosols are more extended, more absorbing, and at higher altitudes than the absorbers of visible light. Transient auroral emissions were observed near the magnetic conjugate point of the K impact site just after that impact. The global auroral activity was fainter than average during the impacts, and a variable auroral emission feature was observed inside the southern auroral oval preceding the impacts of fragments Q1 and Q2.

Thermal Infrared Imaging Spectroscopy of Shoemaker–Levy 9 Impact Sites: Spatial and Vertical Distributions of NH3, C2H4, and 10-μm Dust Emission

“…This implies ȁ10 14 g for the Possible candidates are CS 2 and the high altitude dust visible by HST at UV wavelengths (Clarke et al 1995). K impactor (assuming that it supplies of the solids), that is, 10 times the dust we observe.…”

Mapping Jupiter's Latitudinal Bands and Great Red Spot Using HST/WFPC2 Far-Ultraviolet Imaging

“…The image reduction steps, such as bias and dark current subtraction, flat fielding, and geometric distortion corrections, have been described in Holtzman et al (1995). The cosmic ray removal method used here and developed by Clarke et al (1995b) leaves some residual streaks across the disk in most F160W images. The calibration of the images taken through the F160W, F218W (λ eff = 232 nm, λ = 30 nm), and F255W (λ eff = 271 nm, λ = 34 nm) filters were set by requiring the reflectivities in a 30…”

“…The location of features on Jupiter in the WFPC2 images were determined through edge-finding and navigation programs developed by Clarke et al (1995b). These programs determine the points of inflection along radial scans around the limb, and then iteratively fit an ellipse of the proper shape and size for the disk of Jupiter to these edge points.…”

“…The research extends from part of the first author's doctoral studies. Previous papers on the appearance of Jupiter in the F160W images have focused on auroral activity (Clarke et al , 1998Ballester et al 1996) and on the Shoemaker-Levy 9 (SL-9) impact (Clarke et al 1995b). A description of the F160W filter, observations, and data reduction is presented in Section 2.…”

“…This capability has been achieved with the use of the F160BW filter (henceforth referred to as the F160W filter). The F160W bandpass of 115-215 nm permits simultaneous imaging of the jovian aurora and reflected sunlight (Clarke et al 1995bBallester et al 1996). FUV solar radiation from 115 to 215 nm penetrates the jovian atmosphere to levels ranging from the diffusively separated upper stratosphere (∼10 µbar) to the well-mixed upper troposphere (∼150 mbar), respectively.…”