From: Larry Klaes (lklaes@bbn.com)
Date: Tue Aug 31 1999 - 17:15:20 MDT
On this date twenty years ago, September 1, 1979, the
robot probe Pioneer 11 made the first flyby of the planet
Saturn, thanks to an impressive gravity boost from its
encounter with Jupiter in late 1974.
Though its images would not match in quality with the ones
taken by Voyager 1 and 2 in the next two years, Pioneer 11
was a true pathfinder for those more sophisticated explorers
and all other space vessels to follow.
To quote from the main Pioneer Web site:
http://spaceprojects.arc.nasa.gov/Space_Projects/pioneer/PN10&11.html
Pioneer 11 flew within 13,000 miles of Saturn and took the
first close-up pictures of the planet. Instruments located two
previously undiscovered small moons and an additional ring,
charted Saturn's magnetosphere and magnetic field, and found
its planet-size moon, Titan, to be too cold for life.
Hurtling underneath the ring plane, Pioneer 11 sent back
amazing pictures of Saturn's rings. The rings, which normally
seem bright when observed from Earth, appeared dark in the
Pioneer pictures, and the dark gaps in the rings seen from
Earth appeared as bright rings.
To add to this, in order to show just how exciting and
dangerous the Pioneer 11 Saturn mission was, the probe
came within a celestial hairsbreadth of one of those
previously unknown moons.
Mission planners also considered sending Pioneer 11
through the Cassini Division in Saturn's rings, as they
thought it was an actual empty area in the ring field.
Thankfully they decided not to do this to Pioneer 11,
as the Cassini Division is full of material like the
rest of the rings, only darker.
The last communication from Pioneer 11 was received in
November 1995, shortly before Earth's motion carried it
out of view of the spacecraft antenna.
The spacecraft is headed toward the constellation of Aquila
(The Eagle), Northwest of the constellation of Sagittarius.
Pioneer 11 may pass near one of the stars in the constellation
in about 4 million years.
Like Pioneer 10, it carries the famous Pioneer Plaque with
basic information on the human race that built these first
interstellar explorers from Earth.
For more information on Pioneer 11:
http://www.geocities.com/CapeCanaveral/Launchpad/2099/9711.html
http://www.jpl.nasa.gov/calendar/pioneer11.html
http://sse.jpl.nasa.gov/missions/sat_missns/p11.html
http://spacepc.jpl.nasa.gov/msl/QuickLooks/pioneer10QL.html
http://nssdc.gsfc.nasa.gov/cgi-bin/database/www-nmc?73-019A
http://spaceprojects.arc.nasa.gov/Space_Projects/pioneer/PNhome.html
http://www.nasm.edu/ceps/ETP/SATURN/satpioneer.html
http://spaceart.com/solar/cap/sat/titanp11.htm
http://www.jpl.nasa.gov/saturn/pio_images.html
http://ails.arc.nasa.gov/Images/Astrobiology/AC79-9180.html
http://ails.arc.nasa.gov/Images/Astrobiology/AC79-9107.3.html
http://ails.arc.nasa.gov/Images/Astrobiology/AC74-9006.html
http://www.igpp.ucla.edu/ssc/pdsppi/P11.htm
http://www.islandnet.com/~catherin/thisdaytable9.htm
Larry
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