Comparison of Venera and Magellan Resolutions on Venus

These images show an identical area on Venus as imaged by the U.S. NASA Magellan spacecraft in 1991 (left) and the U.S.S.R. Venera 15/16 spacecraft in the early 1980's (right). In the area seen here, approximately 200 small volcanoes, ranging in diameter from 2 to 12 kilometers (1.2 to 7.4 miles) can be identified. Volcanoes form from the buildup of cooled lavas and ash on a planetary surface. Solids, liquids, and gases can erupt from a volcano. The amount and makeup of the erupting material affects the volcano’s size and shape. Venus displays the greatest diversity of volcanic features among the rocky worlds. Image courtesy of NASA.