Today on Galileo - September 4, 1996
This afternoon, Galileo was scheduled to perform its final orbital adjustment in preparation for the 262 km closest approach to Ganymede on Friday. However, it was cancelled because targeting after the previous adjustment was determined to be sufficiently accurate. Galileo is today at 697,000,000 km from Earth and 33 Jupiter radius distances from Jupiter. Later, the NIMS instrument will perform a series of observations in 5 infrared "colors" (wavelengths) to make a global map of Jupiter.
Today is the start of a series of images taken by Galileo's camera to observe plumes on Io. Scientists want to make a catalog of all plumes more than 50 km high, and this orbit provides them one of only two times during the mission to do so. For the next two days, Galileo will periodically take pictures of a crescent Io against the dark sky as it revolves around the planet, exposing different faces to the spacecraft and allowing scientists to measure the height of any plumes they see.