This Week on Galileo - October 27-November 2, 1997
This week Galileo continues preparations for the last encounter of its primary mission. Execution of the encounter sequence begins next Sunday and features a close flyby of the moon Europa. This encounter, however, is only the first of nine consecutive flybys of Europa, including the eight that are planned as part of the Galileo Europa Mission, the Galileo project's follow-on mission to the primary mission. This week's preparations include returning any remaining data from Galileo's previous encounter with the Jupiter system featuring the moon Callisto, performing the final orbital path correction prior to the Europa flyby on Wednesday, and transmitting the first set of encounter commands to the spacecraft on Thursday.
Playback continues all week, ending just prior to the start of the first encounter set of commands. This week's schedule contains observations from the close flyby of Callisto, the campaign to study Jupiter's auroral regions, the series of observations taken during cruise while the spacecraft was occulted from the sun by Jupiter, and observations of Io and Amalthea.
Observations of Callisto are returned by the Solid-State Imaging (SSI) team and the Near Infrared Mapping Spectrometer (NIMS) team. SSI returns an observation of a smooth plains region, one of crater named Tindr, and one of a region characterized by small rings. These will be used in the continuing effort to understand the different shapes found on Callisto's surface. The NIMS team returns a global observation of Callisto and an observation of the Gipul Catena region. The Gipul region is the longest "chain" of craters on Callisto's surface. The NIMS observations will provide important compositional data of Callisto and this interesting crater chain feature.
As part of the previous encounter's joint instrument campaign to characterize Jupiter's polar auroral regions, observations of these regions continue to be returned by SSI and NIMS. While SSI returns only one image of the north pole region this week, the NIMS team returns a total of six more observations to add to the complement of observations returned in earlier weeks. Four of these observations will be used to construct a map of Jupiter's north pole that will contain information regarding the north pole's cloud structure. A single observation contributing to a map of Jupiter's south pole is also returned this week. The remaining observation is also of the north pole, but focuses on a specific auroral region at 170 degrees west longitude and 65 degrees north latitude.
Observations from the series taken while Galileo was blocked from the sun by Jupiter are only returned by the SSI team this week. The lack of interfering sunlight makes for better chances of detecting the faint rings, lightning, volcanic or auroral signatures. Five of these observations were designed to look for signs of lightning in Jupiter's atmosphere. Two observations looked at Io in hopes of catching faint volcanic plumes or auroral emissions. Six looked at Jupiter's auroral regions (north and south) in hopes of detecting aurora more effectively. Finally, one of the observations was designed to provide information on the vertical and horizontal extent of Jupiter's rings.
Interspersed with the above observations were two more observations from the SSI team. A global observation of Io provides high spatial and spectral coverage of Io while a global observation of Amalthea contributes to the mission-long set designed to obtain 360 degree coverage.
Don't forget about next week's encounter! Daily summaries of what is planned to occur for Galileo will return with the return of "Today on Galileo" on Sunday, 2 November, 1997, at this same URL.