[meteorite-list] New Horizons Sees Changes in Jupiter System

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue, 9 Oct 2007 12:20:27 -0700 (PDT)
Message-ID: <200710091920.MAA13389_at_zagami.jpl.nasa.gov>

Oct. 9, 2007

Dwayne Brown
Headquarters, Washington
202-358-1726
dwayne.c.brown at nasa.gov

Michael Buckley
Johns Hopkins University Applied Physics Laboratory, Laurel, Md.
240-228-7536
michael.buckley at jhuapl.edu

RELEASE: 07-221

NASA SPACECRAFT SEES CHANGES IN JUPITER SYSTEM

LAUREL, Md. - NASA's New Horizons spacecraft provided a new bird's-eye
view of the dynamic Jupiter system as it traveled through the
planet's orbit on Feb. 28.

New Horizons used Jupiter's gravity to boost its speed and shave three
years off its trip to Pluto. Although the eighth spacecraft to visit
Jupiter, New Horizons' combination of trajectory, timing and
technology allowed it to explore details never before observed.

The spacecraft revealed lightning near the Jupiter's poles, the life
cycle of fresh ammonia clouds, boulder-size clumps speeding through
the planet's faint rings, the structure inside volcanic eruptions on
its moon Io, and the path of charged particles traversing the
previously unexplored length of the planet's long, magnetic tail.

"The Jupiter encounter was successful beyond our wildest dreams," said
Alan Stern, principal investigator for the New Horizons mission, NASA
Headquarters, Washington. "Not only did it prove our spacecraft and
put it on course to reach Pluto in 2015, it was a chance for us to
take sophisticated instruments to places in the Jovian system where
other spacecraft could not go. It returned important data that adds
tremendously to our understanding of the solar system's largest
planet and its moons, rings and atmosphere."

The New Horizons team presented its latest, most detailed analyses of
those data Tuesday at the American Astronomical Society's Division
for Planetary Sciences meeting in Orlando, Fla. Results also will
appear in a special section of the Oct. 12 issue of the journal
Science.

>From January through June, New Horizons' seven science instruments
made more than 700 separate observations of the Jovian system.
Jupiter's weather was high on the list, as New Horizons' visible
light, infrared and ultraviolet remote-sensing instruments probed the
planet's atmosphere for data on cloud structure and composition.

Instruments saw clouds form from ammonia welling up from the lower
atmosphere. Heat-induced lighting strikes in the polar regions also
were observed. This was the first polar lighting ever seen beyond
Earth, demonstrating that heat moves through water clouds at
virtually all latitudes across Jupiter.

New Horizons made the most-detailed size and speed measurements yet of
"waves" that run the width of the planet and indicate violent storm
activity below. Additionally, New Horizons snapped the first close-up
images of the Little Red Spot, gathering new information on storm
dynamics. The spot is a nascent storm about half the size of
Jupiter's larger Great Red Spot, or about 70 percent of Earth's
diameter.

The spacecraft captured the clearest images to date of the tenuous
Jovian ring system, showing clumps of debris that may indicate a
recent impact inside the rings or some more exotic phenomenon. Movies
made from New Horizons images offer an unprecedented look at ring
dynamics, showing the tiny inner moons Metis and Adrastea shepherding
the materials around the rings. A search for smaller moons inside the
rings, and possible new sources of the dusty material, found no
bodies wider than a mile.

The mission's investigations of Jupiter's four largest moons focused
on Io, the closest to Jupiter, which has active volcanoes that blast
tons of material into the Jovian magnetosphere and beyond. New
Horizons spied 11 different volcanic plumes of varying size, three of
which were seen for the first time. One, a spectacular 200-mile-high
eruption rising above the volcano Tvashtar, provided a unique
opportunity to trace plume structure and motion. New Horizons' global
map of Io's surface confirms the moon's status as the solar system's
most active body, showing more than 20 geological changes since the
Galileo Jupiter orbiter provided the last close-up look in 2001.

New Horizons' flight down Jupiter's magnetic tail offered a look at
the vast region dominated by the planet's strong magnetic field.
Specifically observing the fluxes of charged particles that flow
hundreds of millions of miles beyond the giant planet, spacecraft
particle detectors saw evidence that tons of material from Io's
volcanoes move down the tail in large, dense, slow-moving blobs.

Designed, built and operated by the Johns Hopkins University Applied
Physics Laboratory, Laurel, Md., New Horizons lifted off in January
2006. The fastest spacecraft ever launched, it reached Jupiter in
just 13 months. New Horizons is now approximately halfway between the
orbits of Jupiter and Saturn, more than 743 million miles from Earth.
It will fly past Pluto and its moons in July 2015, then head deeper
into the Kuiper belt of icy, rocky objects on the planetary frontier.
New Horizons is the first mission in NASA's New Frontiers Program of
medium-class spacecraft exploration projects.

For more details on the findings, visit:

http://www.nasa.gov/newhorizons

        
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Received on Tue 09 Oct 2007 03:20:27 PM PDT