The second planet from the Sun, Venus, is almost a twin to Earth in size and mass. With a surface temperature 462° C, even lead will melt on Venus. The atmosphere is 96% carbon dioxide and has a pressure 92 times that of Earth. Venus is the hottest planet.
The thick atmosphere of Venus makes observations of the surface with visible light
impossible. The surface of Venus was mapped using radar by the Magellan probe. This
map shows 167 volcanoes over 100 km across and almost 1000 impact craters, all younger
than about 600 million years.
The surface of Venus gets totally recycled every few hundred million years. Interior heat builds up and melts the entire crust over a period of about 100 million years.
While all the other planets rotate counter-clockwise on their axis, Venus rotates clockwise with a day of 243 Earth days. This reverse rotation was caused by a huge impact that reversed the planet's spin and gave it a very long day. On Venus the Sun rises in the west and sets in the east.
The orbit of Venus is inclined slightly relative to Earth's orbit, so it usually does not cross the face of the Sun as seen from Earth. Venus transits occur every 120 years or so, the last being June 5, 2012. The next transit is not until Dec 10, 2117.
Because it has an orbit interior to Earth, Venus goes through phases just like the Moon. Discovery of these phases by Galileo in 1610 proved that the Sun was the center of the Solar System.
|Semi-major axis||1.08 x 108 km
|Orbital Period||224.7 d|
|Mean radius||6051.8 km
|Mass||4.8676 x 1024 kg
|Mean density||5.243 g/cm3|
|Surface gravity||8.87 m/s2