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

[Ron Baalke]

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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