This Week on Galileo - March 10-16, 1997
Galileo continues returning data from its previous pass through Jupiter's system. The playback focus moves away from Europa and back to Jupiter, the magnetosphere, and the other moons. On Thursday evening, the spacecraft is scheduled to perform the next orbit trim maneuver. This maneuver will fine tune the spacecraft's path and put it on the right course for its next encounter in early April. In addition, on Sunday night, the spacecraft will perform another turn to keep its radio antenna pointed toward earth.
The Jupiter observations returned during this week once again contain data on the white ovals in Jupiter's atmosphere. These particular observations were taken by NIMS (Near Infrared Mapping Spectrometer) and PPR (Photopolarimeter- Radiometer). Many of these observations are taken over a range of solar phase angles, from 95 deg to 150 deg. Remember that small solar phase angles occur when the sun is directly behind the spacecraft and most of the target is lit by the sun. These medium to high phase angles mean the sun is lighting Jupiter from the side and from behind. The range of phase angles allows the instruments to look at different types of reflected light which allows scientists to identify different properties of the particles in Jupiter's atmosphere. North-south strip observations are also returned this week. These observations provide data that allow scientists to place the white oval observations in the context of what was happening in the rest of Jupiter's atmosphere.
The fields and particles instruments' high-rate recording as Galileo flew through Jupiter's magnetic equator is also scheduled to be returned this week. In this region of the magnetosphere, it is thought that fresh plasma is constantly being generated and transported away to the outer boundaries of the magnetosphere. This data will provide information on the heart of the magnetosphere - how the plasma is generated and transported away, and what effect activity here has on the rest of the magnetosphere.
The remaining observations returned this week are comprised of observations of Io, Ganymede and Amalthea. Io observations include the completion of a surface map from the Europa-4 encounter, chemical monitoring and the search for volcanic hot spots. The Ganymede observations are part of multi- orbit campaigns to characterize the surface of Ganymede and fill in gaps in data obtained during the Voyager spacecraft flybys of the Jupiter system. Finally, the Amalthea observation is also one of many performed and planned during the orbit tour that will be used to determine the global shape and morphology of Amalthea.