nees plirofories gia ta ifaisteia tis Io

[johnme]

Contact: Guy Webster/JPL (818) 354-6278

Lori Stiles/University of Arizona (520) 626-4402

 

IMAGE ADVISORY March 29, 2001

 

TWO SPACECRAFT WATCH A TOWERING INFERNO ON IO

 

Two NASA spacecraft jointly observing Jupiter's moon Io

this winter captured images of a towering volcanic plume never

seen before and a bright red ring of fresh surface deposits

surrounding its source.

 

Combined information from images taken by the Cassini

and Galileo spacecraft indicates the new plume is about the

same size -- nearly 400 kilometers or 250 miles high -- as a

long-lived plume from Io's Pele volcano. Pele's plume and ring

are also seen in the new images.

 

The images and further information about them are

available online from NASA's Jet Propulsion Laboratory,

Pasadena, Calif., at http://www.jpl.nasa.gov/pictures/jovianmoons , from the web

sites of the Cassini Imaging Science team at the University of

Arizona, Tucson, at http://ciclops.lpl.arizona.edu/ and from

the University of Arizona's Planetary Image Research

Laboratory, at http://pirlwww.lpl.arizona.edu/Galileo/Releases/ .

 

The new plume originates from a volcanic feature named

Tvashtar Catena near Io's north pole. Scientists were

astounded to discover so large a plume so near the pole,

because all active plumes previously detected on Io have been

over equatorial regions and no others have approached Pele's

in size, said University of Arizona planetary scientist Dr.

Alfred McEwen.

 

Galileo might pass right through the Tvashtar plume in

August, if the plume persists until then. The spacecraft will

be flying over that part of Io at an altitude of 200

kilometers (124 miles). Material in the plume is tenuous

enough to present little risk to the spacecraft, and passing

through it could give an opportunity to analyze the makeup of

the plume, said Dr. Torrence Johnson, Galileo project

scientist at JPL.

 

Cassini is a cooperative project of NASA, the European

Space Agency and the Italian Space Agency. JPL manages Cassini

and Galileo for NASA's Office of Space Science, Washington,

D.C. JPL is a division of the California Institute of

Technology in Pasadena.