• Publications
  • Influence
The Far-Ultraviolet Oxygen Airglow of Europa and Ganymede
Far-UV spectra of Europa and Ganymede, acquired by the Hubble Space Telescope Goddard High Resolution Spectrograph, indicate that, in addition to faintly reflected sunlight, both satellites emit O IExpand
Detection of an oxygen atmosphere on Jupiter's moon Europa
The detection of atomic oxygen emission from Europa is reported, which is interpreted as being produced by the simultaneous dissociation and excitation of atmospheric O2 by electrons from Jupiter's magnetosphere. Expand
Transient Water Vapor at Europa’s South Pole
Europa's Plumes Jupiter's moon Europa has a subsurface ocean and a relatively young icy surface, and spectral images taken by the Hubble Space Telescope show ultraviolet emissions from the moon's atmosphere that are consistent with two 200-km-high plumes of water vapor. Expand
The On-Orbit Performance of the Space Telescope Imaging Spectrograph
The Space Telescope Imaging Spectrograph (STIS) was successfully installed into the Hubble Space Telescope (HST) in 1997 February, during the second HST servicing mission, STS-82. STIS is a versatileExpand
Sputtering of sodium on the planet Mercury
The discovery of a column density of neutral sodium vapour (∼1011–1012 atoms Na cm−2) associated with the solar-facing side of the planet Mercury1 has rekindled interest in the possible presence ofExpand
OH in Saturn's magnetosphere: Observations and implications
The discovery of OH in Saturn's inner magnetosphere changed our view of this region from one where plasma dominated the physics to one where neutrals are dominant. We revisit Hubble Space TelescopeExpand
Transient Water Vapor at Europa's
In November and December 2012, the Hubble Space Telescope (HST) imaged Europa’s ultravioletemissions in the search for vapor plume activity. We report statistically significant coincidentsurpluses ofExpand
Discovery of gaseous S2 in Io's Pele plume.
Spectroscopy of Io's Pele plume against Jupiter by the Hubble Space Telescope in October 1999 revealed absorption due to S2 gas, and probably also SO(2) gas with a column density of 7 +/- 3 x 10(16) per square centimeter. Expand
Exospheres and Atmospheric Escape
Aeronomy is a description of the physics and chemistry of the upper atmospheres and ionospheres of planetary bodies. In this chapter we consider those processes occurring in the upper atmosphere thatExpand
HST/STIS Ultraviolet Imaging of Polar Aurora on Ganymede
We report new observations of the spectrum of Ganymede in the spectral range 1160-1720 A made with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope (HST) on 1998 OctoberExpand