Today on Galileo - September 17, 1997
Galileo turns its attention to Jupiter today, the fifth calendar day of the encounter. The first set of encounter commands are completed and the second set, transmitted to the spacecraft on Monday, begins to execute today. A few residual observations of Callisto and observations of Io and Ganymede complete the observation schedule.
The observation plans for Jupiter during this encounter period include a more or less standard set of observations: brightside and darkside maps, North-East-West-South maps, North-South strips, hot spot observations, regional and thermal maps. These observations are complimented by a set of observations that concentrate on the north polar region of Jupiter's atmosphere, including aurora and regions known as haze zones. These haze zones, as their name suggests, are regions of hazy clouds that are associated with and driven by the production of aurora on Jupiter. The observations of these regions will be coordinated among all of the remote sensing instruments for a complete understanding of the processes involved in the production of these hazy cloud regions.
This morning's observation schedule includes observations of aurora on Jupiter performed by the Ultraviolet Spectrometer (UVS) and the Solid State Imaging (SSI) camera. A single observation of aurora is taken by SSI in the evening. Three haze zone observations are taken by the UVS instrument during the day. Filling in the gaps between these observations are a couple of darkside maps and a couple of brightside maps performed by the UVS instrument. These observations, repeated during almost each encounter, provide information regarding the distribution and dynamics of energy and hydrogen on a global scale.
The day is sprinkled with the observations of Callisto, Ganymede and Io. The Near Infrared Mapping Spectrometer (NIMS) takes a global look at Callisto while later in the day the UVS instrument looks for evidence of a neutral cloud of particles surrounding Callisto. Ganymede is observed by the UVS instrument from a view not possible from Earth. Io is observed by the UVS and SSI instruments while eclipsed from the Sun by Jupiter and Io's torus is observed remotely by the UVS instrument.