THE SURFACE OF VENUS

V enus is relatively young from a geological perspective. The planet was completely resurface 300 to 500 million years ago, but scientists are not quite sure how or why. The planet's surface consists of vast plains and mountain or highland region that have been deformed by geological activity. Maxwell Montes in Ishtar Terrais the highest peak on Venus. The Aphrodite Terra highlands extends almost halfway around the equator.

T he surface of Venus is scarred by a series of randomly scattered impact craters. Small craters less than 2 km (1.2 miles) are almost non existent due in large part to its thick atmosphere. The exception to this is when a large meteor or asteroid shatters on impact with the planets causing what is called crater clusters.

G iant calderas more than 100 km (62 miles) in diameter are found on Venus. This is quite impressive considering that most terrestrial calderas only extend a few kilometers. There are a few unique geological formations on Venus. The first are known as coronae, which are large circular to oval features, surrounded by steep cliffs and measure hundreds of kilometers across. They are thought to be caused by the uprising of the planet's mantle. Another unique feature of Venus are archnoids as seen in this picture. Archnoids are circular to elongated features very similar to coronae. They might have been created when molten rock seeped through fractures or faults in the planet's crust, which would produce these radiating dikes.

V enus has seen a lot of volcanic activity in its lifetime. At least 85% of the surface is covered with volcanic rock. Huge lava flows that measure kilometers in length flooded the lowlands and created vast plains. Volcanoes are very numerous. Large volcanoes are interspersed with over 100,000 smaller shield volcanoes. The eruption of these volcanoes has carved deep channels into the surface, one extends nearly 7,000 km (4,300 miles).