COMPOSITION Venus's composition primarily comprises a rocky mantle and iron-nickel core. Its atmosphere is predominantly carbon dioxide (96.5%) with traces of nitrogen and sulfur dioxide. Thick clouds of sulfuric acid and sulfur dioxide obscure the surface. The surface is mainly basaltic rock with significant volcanic features, suggesting ongoing or recent volcanic activity. The planet lacks water in liquid form due to high temperatures, which caused any ancient oceans to evaporate. Venus's geology and atmosphere make it a scorching, corrosive, and hostile world.