PIA09252: Alice Views Jupiter and Io

Alice Views Jupiter and Io


This graphic illustrates the pointing and shows the data from one of many observations made by the New Horizons Alice ultraviolet spectrometer (UVS) instrument during the Pluto-bound spacecraft's recent encounter with Jupiter. The red lines in the graphic show the scale, orientation, and position of the combined "box and slot" field of view of the Alice UVS during this observation.

The positions of Jupiter's volcanic moon, Io, the torus of ionized gas from Io, and Jupiter are shown relative to the Alice field of view. Like a prism, the spectrometer separates light from these targets into its constituent wavelengths.

Io's volcanoes produce an extremely tenuous atmosphere made up primarily of sulfur dioxide gas, which, in the harsh plasma environment at Io, breaks down into its component sulfur and oxygen atoms. Alice observed the auroral glow from these atoms in Io's atmosphere and their ionized counterparts in the Io torus.

Io's dayside is deliberately overexposed to bring out faint details in the plumes and on the moon's night side. The continuing eruption of the volcano Tvashtar, at the 1 o'clock position, produces an enormous plume roughly 330 kilometers (200 miles) high, which is illuminated both by sunlight and "Jupiter light."

Cataloging Keywords:

Name Value Additional Values
Target Jupiter Io, Pluto, Sun
System Jupiter Pluto
Target Type Planet Dwarf Planet, Satellite, Sun
Mission New Horizons
Instrument Host New Horizons
Host Type Flyby Spacecraft
Instrument Alice Ultravilet Spectrometer
Extra Keywords Atmosphere, Color, Plume, Ultraviolet, Volcano
Acquisition Date
Release Date 2007-04-02
Date in Caption
Image Credit NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute
Source photojournal.jpl.nasa.gov/catalog/PIA09252
Identifier PIA09252