This picture of Io was taken by Voyager 1 on the morning of March 5, 1979 at a range of about 92,000 km (55,000 mi.). The view is of the terminator region centered at 60 degrees south latitude and 276 degrees longitude. North is toward the upper left-hand corner of the picture. The Sun is shining from lower-left to upper-left. Shadows cast by cliffs are clearly visible near the terminator. The long valley which parallels the terminator is about 300 km long and 50 km wide. It may be a fault trough due to crustal deformation. Other cliffs which parallel the trough may also be faults. The large bright patch in the lower left portion of the picture, and the two black spots are probably some type of surface deposits. The Voyager Project is managed and controlled by the Jet Propulsion Laboratory for NASA's Office of Space Science.