This full resolution radar mosaic centered at 14 degrees north latitude, 72 degrees east longitude, shows an oblique view of the impact crater Riley, named for Margaretta Riley, a 19th Century botanist. This view was prepared from two left-looking Magellan radar images acquired with different incidence angles. Because the relief displacements of the two images are different, depths from the crater rim to the crater floor and heights of the crater rim and flanks above the surrounding plains can be measured. The crater is 25 kilometers (15.5 miles) in diameter. The floor of the crater is 580 meters (1,914 feet) below the plains surrounding the crater. The crater's rim rises 620 meters (2,046 feet) above the plains and 1,200 meters (3,960 feet) above the crater floor. The crater's central peak is 536 meters (1,769 feet) high. The crater's diameter is 40 times the depth resulting in a relatively shallow appearance. The topography is exaggerated by 22 times to emphasize the crater's features. This oblique view was produced from two left-looking radar stereo image mosaics utilizing photogrammetric software developed by the Solar System Visualization project and the Digital Image Animation Laboratory at JPL's Multimission Image Processing Laboratory. This colorized picture of Venus was taken February 14, 1990 at a distance of almost 1.7 million miles, about 6 days after Galileo's closest approach to the planet. It has been colorized to a bluish hue to emphasize subtle contrasts in markings and to indicate that it was taken through a violet filter. Features in the sulfuric acid clouds near the top of the planet's atmosphere are most prominent in violet and ultraviolet light. This image shows the east-to-west-trending cloud banding and the brighter polar hoods familiar from past studies of Venus. The features are embedded in winds that flow from east to west at about 230 mph. The smallest features visible are about 45 miles across. An intriguing filamentary dark pattern is immediately left of the bright region at: the subsolar point (equatorial "noon"). North is at the top and the evening terminator is to the left. The Galileo Project is managed for NASA's Office of Space, Science and Applications by the Jet Propulsion Laboratory; its mission is to study Jupiter and its satellites and magnetosphere after multiple gravity-assist flybys at Venus and Earth.
