From: Jet Propulsion Laboratory
Posted: Tuesday, October 30, 2001
The focus for Galileo this week is playback of the recorded data from the October 15 flyby of Io. First up is the calibration for the Photopolarimeter Radiometer instrument (PPR), which began our observing sequence. PPR then turns its attention to several observations of Jupiter. These measurements were made of a region of vortex-like storms near the north pole of the giant planet, and of a long-lived white oval storm that has been the subject of several observations during our stay in the Jupiter system. Scientists also expect to see data from a thermal map of the dark side of Io, taken while the spacecraft was still 11 hours away from its closest approach.
The bulk of the week is taken up with the return of a two-hour-long recording by the suite of instruments that measure the electromagnetic fields and energetic particles that encircle the planet. These instruments are the Energetic Particle Detector, the Heavy Ion Counter, the Magnetometer, the Plasma Subsystem, and the Plasma Wave Subsystem. The recording was made while the spacecraft was passing through the Ramp region of the Io Torus. The torus is a doughnut-shaped area of increased radiation and particle density that nearly coincides with the orbit of Io. The Ramp is the transition between the background magnetosphere and the torus. It is a region where the ion density and temperature of the environment increase sharply, making it an intriguing target for exploration.
Also during this week the Magnetometer and Dust Detector instruments continue to collect data about the immediate environment of the spacecraft as the hardy explorer increases its distance from Jupiter from 100 to 125 Jupiter radii (7.1 million to 8.9 million kilometers, or 4.4 million to 5.5 million miles). These data are stored within the two instruments' individual computer memories and periodically transmitted to Earth.
The Extreme Ultraviolet Spectrometer instrument is also collecting data, studying the solar variation in the interplanetary hydrogen and helium abundances. This instrument also stores its collected data in internal buffer memory and periodically feeds this data into the main information stream coming from the spacecraft.
For more information on the Galileo spacecraft and its mission to Jupiter, please visit the Galileo home page at one of the following URL's:
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