Today on Galileo - June 27, 1997
The last three closest approach events of the encounter period occur today on Galileo! The spacecraft first passes by Europa at about 3:10 A.M. PDT at a distance of nearly 1.2 million kilometers (746,000 miles). The closest approach to Jupiter follows closely at about 4:52 A.M. PDT at a distance of 770,000 kilometers (479,000 miles). Toward the end of the day, about 7:30 P.M. PDT, the spacecraft passes by Io at a distance of 607,000 kilometers (377,000 miles).
The day's observations focus primarily on Jupiter's atmosphere. Galileo continues to observe the Great Red Spot and plume head regions. In addition, NIMS (Near Infrared Mapping Spectrometer) performs a series of observations of Jupiter's south pole, part of a complete map of the south pole. Finally, a north-south strip observation is performed by PPR (Photopolarimeter Radiometer).
This encounter's series of minor satellite observations is completed today. Divided roughly evenly between the four target bodies (Metis, Adrastea, Amalthea and Thebe), the 20 observations form the bulk of the campaign of observations of the minor satellites for the entire Galileo orbital tour. This campaign is designed to provide global views of the satellites and determine shape and composition. The observations taken during this encounter range from 6.5 to 14.5 kilometers per pixel (4 - 9 miles per pixel).
Observations of Io comprise the remainder of the observation schedule for today. These observations include monitoring for active plumes and changes in surface temperatures, features, and chemistry. The plumes targeted during this encounter include Loki, Marduk, Pele and Surt.