This Week on Galileo - March 3-9, 1997
This week's playback plans are devoted exclusively to observations of Europa, the prime target of Galileo's encounter last month. Data from both the remote sensing instruments and the fields and particles instruments is scheduled for transmission to Earth. Also during the week, a new set of commands is transmitted to the spacecraft. This set will govern the spacecraft's activity from this Friday through just prior to the Galileo's next encounter.
Europa was observed at small solar phase angles during the last encounter which means most of the moon (as seen from the spacecraft) was illuminated by the sun. The observations returned during this week will provide data on what the surface is made of, how it is shaped, and will allow comparison of different types of surfaces.
SSI (Solid State Imaging camera) returns two pairs of observations of bright material and a relatively fresh crater feature on Europa's surface. Each pair is made up of one regional observation that will provide context information for the second observation which is high resolution. The bright material observations will allow comparison with dark material samples also obtained in the last encounter and with high latitude samples scheduled for the last encounter (E11 - Europa 11) of Galileo's prime mission. The high resolution samples will allow for comparisons using features as small as tens of meters in size. The crater feature observations are expected to provide clues to what is directly under Europa's surface.
NIMS (Near Infrared Mapping Spectrometer) returns several observations of Europa's surface. They are designed to provide information on the composition of Europa's surface. One of these observations will be used to tell the difference between regions of hexagonal- looking young ice from older ice with no specific form. Another observation focused on a very lineated region, which may be an indication of activity below Europa's surface.
PRR (Photopolarimeter-Radiometer) is scheduled to return an observation of Europa's darkside. This observation is used to characterize the temperatures of brightspots present on Europa during the nighttime. It may also provide clues regarding any heat sources that may be affecting the constitution of Europa's surface.
Finally, the fields and particles data that is returned from the time of encounter closest approach is a continuation of efforts to understand the interaction between the Jovian moons and the Jovian magnetosphere.