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PHOTO CAPTION                                     P-47971
                                                  October 23, 1996

Io, the most volcanic body in the solar system, is seen in front of
Jupiter's cloudy atmosphere in this image from NASA's Galileo spacecraft,
now orbiting the giant planet. This newly processed image is the best and
highest resolution view of Io produced thus far by Galileo. Galileo was
about 487,000 kilometers (about 302,000 miles) from Io when this was taken
on September 7, 1996, and Jupiter was about 908,000 kilometers (about
564,000 miles) away. The image is centered on the side of Io that always
faces away from Jupiter. The color in the image is composed of data taken in
the near-infrared, green and violet filters of Galileo's solid-state imaging
camera, and has been enhanced to emphasize the extraordinary variations in
color and brightness that characterize Io's volcano-pocked face. The black
and bright red materials correspond to the most recent volcanic deposits,
probably no more than a few years old. The near-infrared filter makes
Jupiter's atmosphere look blue. The active volcano Prometheus is seen near
the right-center of the disk. Scientists are noting many changes that have
occurred on Io's surface since the Voyager flybys 17 years ago, and even a
few changes in the two months since Galileo's imaging of Io this summer.

Launched in October 1989, Galileo entered orbit around Jupiter on December
7, 1995. The spacecraft's mission is to conduct detailed studies of the
giant planet, its largest moons and the Jovian magnetic environment. The Jet
Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of
Space Science, Washington, DC.