Galileo Shows New Views of Io's Hyperactive Volcanoes

Feb. 26, 2001

(Media contacts: Guy Webster, NASA Jet Propulsion Laboratory, (818) 354-6278;Lori Stiles, University of Arizona, (520) 626-4402)

New imagery of Jupiter's moon Io, including a flyover animation of one volcanic area and three-dimensional views of another, shows a world so volcanically hyperactive that nearly its entire surface is likely to be lava that's still in various stages of cooling.

The images are based on observations made by NASA's Galileo spacecraft during flights close to Io in 1999 and 2000. They are available online from the University of Arizona's Planetary Image Research Laboratory, Tucson, at and from the Jet Propulsion Laboratory, Pasadena, Calif., at

Scientists are studying these images and other Galileo data for a better understanding of how Io's mountains form, how much heat Io generates internally and other questions. The extreme heat of the lava erupting on Io makes that world today a model for the type of volcanism Earth experienced billions of years ago.

Galileo has been orbiting Jupiter and its moons since December 1995. More information about the mission is available at

JPL, a division of the California Institute of Technology, Pasadena, manages Galileo for NASA' s Office of Space Science, Washington, D.C.

The Galileo Solid State Imaging team is headed by Michael Belton of National Optical Astronomy Observatories in Tucson, Ariz. University of Arizona Lunar and Planetary Laboratory scientist Alfred McEwen and his group process and analyze images at the LPL Planetary Image Research Laboratory (PIRL).


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