Venus is the second planet from the Sun. This bright planet has been admired by man since antiquity as it appears in the east just before sunrise. For this reason it is known as the morning star. Venus is also known as the evening star because it also appears in the east around sunset.
Venus was named after the Roman goddess of love. For a long time it was considered a sister of the Earth, as it is similar in size to our planet. It was hoped that the dense cloud cover of Venus concealed a damp, fertile landscape capable of supporting life. Some scientists even believed that life might already exist on Venus, but further studies could not confirm this.
The diameter of Venus is 12,103 kilometers. Its mean distance from the Sun is 108 million kilometers. It rotates slowly about its own axis and in the opposite direction to that of the Earth. From the surface of Venus the Sun would be seen to rise in the west and set in the east. When the Earth and Venus are close together on their orbits, we always see the same side of the planet.
One Venus day, i.e. the planet's period of rotation, is 243 Earth days. The composition of Venus is very similar to that of the Earth. The core, which consists of iron, is surrounded by a mantle and a crust of rock. Venus rotates very slowly and for this reason does not produce a magnetic_field.
The atmosphere of Venus is so dense that the pressure there is 90 times higher than that on Earth. The temperature is always about 470┬░ Celsius, regardless of which side of the planet is exposed to the Sun. This greenhouse_effect is caused by the high percentage of carbon dioxide in the atmosphere. The radiation from the Sun can penetrate but the heat cannot escape.
Besides its 95% carbon dioxide content, the atmosphere of Venus contains nitrogen as well as traces of water vapor, argon, neon, sulfur dioxide and carbon monoxide. The clouds lie at an altitude of between 40 and 100 kilometers. Wind movements directly on the surface are minimal. They become greater at higher altitudes.
The cloud belts rotate faster than the planet itself, circling the planet in about four days. They also circulate from the poles to the equator, where great storms rage at speeds of up to 400km/h. These are similar to the jet streams on Earth.
