This high resolution (35-40 meters, or yards, per picture element) strip of images was acquired by NASA's Galileo spacecraft on 11 October 1999 during its 24th orbit. The mosaic shows a portion of the 100 kilometer (60 mile) long lava flow that appeared during the 17 years between the Voyager flybys and Galileo's first images of Io.

The dark flows have intricate margins that are characteristic of a type of lava flow seen on Earth called pahoehoe. The source of the lava flows is a 25 kilometer (16 mile) long fissure that extends to the east of the central vent off the mosaic to the upper left. Some of the lava flows at the western end of the mosaic have channels with bright floors. These channels may have been carved by sulfur lava flows or they may have been carverd by silicate lava flows which were later covered by bright material.

North is to the top of the mosaic. The images were taken at a distance of 3500 - 4000 kilometers (2200 - 2500 miles) from Io. The large doses of radiation to which the spacecraft is subjected each time it passes close to Jupiter caused a problem with Galileo's camera which resulted in scrambling of these images. Engineers at JPL were able to reconstruct the images, but black stripes remain where some data could not be recovered. The streaks from lower left to upper right are artifacts from the reconstruction.

Image produced by: Moses Milazzo, Planetary Image Research Lab. (PIRL), Lunar and Planetary Lab. (LPL), University of Arizona

The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at http://galileo.jpl.nasa.gov/. Background information and educational context for the images can be found at http://galileo.jpl.nasa.gov/images/io/ioimages.html.

NASA's Planetary Photojournal PIA-02537

May 19, 2000