|Diameter||12164 km, 0.95 x Earth's|
|Average Density||5.24 g/cm3|
|Average Distance from Sun||108 x 106km = 0.723 AU|
|Eccentricity of Orbit||0.007|
|Inclination of Equator to Orbit||177.36°|
|Inclination of Orbit to Ecliptic||3.4°|
|Colour||White cloud cover.
Surface is brown rock.
|Atmosphere||Carbon dioxide (96.5%)
Clouds: Sulphuric acid
|Length of Day||243 days|
|Length of Year||224.7 days|
|No. of Moons||None|
|Surface Pressure||90 x Earth's|
|Gravity||0.903 x Earth's|
|Escape Velocity||10.36 km/s|
Venus is the second planet in our Solar System and is the brightest object in the sky after the Sun and Moon. The apparent magnitude can reach a value of – 4.7. This is due to the high albedo caused by the almost continuous layer of clouds that cover the whole surface. These clouds are made of sulphuric acid and increase the runaway greenhouse effect on the planet. Venus is also highly volcanic, adding to the large amounts of sulphur dioxide in the atmosphere.
The temperature on the surface of Venus is hot enough to melt lead. The greenhouse effect has meant that the planet is hotter than Mercury, even though it is twice as far from the Sun. All of the water has boiled away and there is a large amount of lightning seen in the atmosphere. The pressure on Venus is the same as at 1km beneath the sea on Earth. The incredibly high pressures and temperatures mean that it is very difficult to land a spacecraft on the surface, and the atmosphere is also harmful to metal. The Soviet Venera probes that landed on Venus only lasted for a few minutes before they were destroyed.
The planet has been mapped by radar from space, showing a rocky and mountainous surface like the Earth, broken by large, open plains. All of the features on Venus are named after famous women except for the first one found: Maxwell Mountain.
Venus has the most circular orbit of all the planets. The axis of rotation is at an angle of almost 180 degrees to the direction of orbit. This means that the direction of rotation is retrograde (in the opposite direction to the orbital motion) while all of the other planets, with the possible exception of Uranus, rotate prograde (in the same direction as the orbital motion). The planet rotates fairly slowly, meaning that a day on Venus lasts longer than a year.
Authors: Carolyn Brinkworth and Claire Thomas
Last updated: July 2001