Density - 5.2g/cm³,

Venus has a surface temperature of about 470 degrees; the atmsopheric pressure at the surface is 90 times greater than Earth's, about the same as the pressure at a depth of 1 km in Earth's oceans. Strong (350 kph) winds exist at the cloud tops but winds at the surface are no more than a few kilometers per hour. Although Venus has a dense atmosphere, the surface reveals no evidence of substantial wind erosion, and only evidence of limited wind transport of dust and sand.

Venus's atmosphere is nearly devoid of water, made up of 97 percent carbon dioxide; its upper clouds contain sulfuric acid. At one time Venus may have had more water. The high surface temperature is created by the greenhouse effect, with temperatures too hot for water to exist on its surface.

Venus has no moons, and no magnetic field has been detected. It rotates on its axis in a retrograde direction -- that is, opposite that of Earth and most of the other planets -- very slowly, once every 243 Earth days.

Craters shown in the radar images from Magellan indicate that Venus's surface appears relatively young -- resurfaced about 500 million years ago by widespread volcanic eruptions.

The surface of Venus is mostly covered by volcanic materials. Volcanic surface features, such as vast lava plains, fields of small lava domes, and large shield volcanoes are common. The presence of lava channels over 6,000 kilometers long suggests river-like flows of extremely low-viscosity lava that probably erupted at a high rate. Venus is peppered with hundreds of thousands to millions of volcanoes distributed more or less randomly around the planet. Although Venus may still have active volcanoes, no visible outpourings of lava have yet been detected in comparisons of Magellan images between one eight-month orbital cycle and another.

Although Venus is similar in size to Earth, its interior is likely different in major ways. In particular, Venus seems to lack an "asthenosphere," a buffer layer within Earth between the outer part of the planet and the mantle beneath. Judging from the surface features of Venus, it is unlikely that a tectonic system operates like the plate tectonic system on Earth.