This Week on Galileo September 3-9, 2001
This week the focus for the Galileo spacecraft is playback of the recorded
data that was acquired during the August 5 flyby of Io and Jupiter. There
are two observations scheduled to be returned this week, both from the Near
Infrared Mapping Spectrometer instrument (NIMS), and both of regions on Io.
The first observation is a map of the Amirani hot spot and the Maui region
in Io’s northern hemisphere, looking for temperature variations, sulphur
dioxide distribution, and a study of an uncharacterized spectral absorption
feature that occurs near a wavelength of 1 micron (1 micrometer). The
origin of this spectral feature is unknown, although many minerals
containing iron have absorptions in this region. There is more of this
absorber near the south pole of Io than elsewhere. Scientists may be able
to more closely constrain the possible mineral compositions of the absorber
if we can resolve its relationship to hot spots and sulphur dioxide deposits.
The second observation is a regional scale map which covers most of the
sunlit portion of Io that was seen by the spacecraft beginning aproximately
an hour and fifty minutes after closest approach. The main regions of
interest in this view are Prometheus and Emakong, which are near Io’s
equator. Prometheus is one of the larger and more active volcanoes on Io,
and was one of the active features first seen by the Voyager spacecraft
during their flybys in 1979. In keeping with the everchanging nature of
this active moon, a new volcanic region was seen in this area by Galileo
during our previous flyby in late May. This new area is also scrutinized by
this observation.
For more information on the Galileo spacecraft and its mission to Jupiter,
please visit the Galileo home page at one of the following URL’s:
