This Week on Galileo November 26 – December 2, 2001
This week’s major spacecraft activity comes on Friday, when Galileo
performs an orbit trim maneuver. This is the second of three rocket engine
burns planned to occur between the 32nd and 33rd close satellite encounters
since the aging spacecraft went into orbit. This one is scheduled to take
place near apojove, or the farthest point in the orbit from the giant
planet Jupiter. Apojove occurs on Saturday, at about 1:30 p.m. PST, when
the distance from Galileo to Jupiter is 160.9 of Jupiter’s radii. This
translates into 11.5 million kilometers, or 7.15 million miles, which is
fully 1/13 the distance from the Earth to the Sun.
This is not the farthest from Jupiter that the spacecraft has been since
first arriving in orbit in December 1995. That honor goes to the 28th
orbit, when we reached a distance of nearly 290 Jupiter radii (20.7 million
kilometers or 12.9 million miles). But that distance in turn will be
surpassed in our 34th orbit in April 2003 when we stretch out to 369.5
Jupiter radii (26.4 million kilometers or 16.4 million miles) before making
our final plunge into Jupiter’s atmosphere in September.
The remainder of the week is filled with the steady collection of real-time
data by the Magnetometer, the Dust Detector, and the Extreme Ultraviolet
Spectrometer, and by the continued playback of recorded data from the
October 15 flyby of Io.
While the Fields and Particles instruments continue the return of a
1.5-hour recording centered on the closest approach of Galileo to Io, the
Near Infrared Mapping Spectrometer (NIMS) and the Solid State Imaging
camera (SSI) play back data also acquired when Galileo was near its closest
point to Io. NIMS observations will provide thermal mapping and sulfur
dioxide distribution around Emakong caldera (an extended volcanic crater),
Tupan Patera (an active volcanic site that displays distinctive red
deposits), and Chaac caldera. An additional observation will examine a
newly discovered hot spot.
SSI will return pictures of Tohil Mons and Patera, the Mycenae Regio,
Culann Patera, and a region near the giant volcano Prometheus, taken while
those features were near the terminator, or day-night boundary. Additional
views are of the Gish Bar hot spot and a color look at the active volcanic
patera Tupan. SSI will also return the first medium-resolution look at the
Tvashtar volcanic region since a large plume eruption occurred there in
late 2000.
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:
