Voyager 1 Image of Io
53K
53K
PUBLIC INFORMATION OFFICE JET PROPULSION LABORATORY CALIFORNIA INSTITUTE OF TECHNOLOGY NATIONAL AERONAUTICS AND SPACE ADMINISTRATION PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011 PHOTO CAPTION P-26241Ac 12/21/83
Maasaw Patera -- a giant caldera, or volcanic-collapse crater, on the Jovian satellite Io -- dominates this Voyager 1 image from March 1979. The caldera and the surrounding surface markings are much like the ones geologists see on Earth and on Mars. The principal difference is Maasaw Patera's great size, as the caldera alone is 50 kilometers across. Two levels in Maasaw Patera suggest stages of collapse. The greater portion is 0.7 kilometers deep, according to calculations based on the shadows in the caldera. The remaining portion, at the upper right of the caldera, is about 2 kilometers deep. At some point, geologists believe, upwelling molten material must have overflowed the rim of the caldera to produce streams of lava hundreds of kilometers long. This mosaic was produced by Alfred S. McEwen of the U.S. Geological Survey, Flagstaff, Ariz. His technique uses high- resolution images for spatial detail and low-resolution images for color data. The Voyager project is managed for NASA by the Jet Propulsion Laboratory,Pasadena, Calif.