Venus

Venus is the second planet from the Sun. It has a day longer than a year. The year length of Venus is 225 Earth days. The day length of Venus is 243 Earth days.

Venus is a terrestrial planet because it has a solid, rocky surface like other planets in the inner Solar System. Astronomers have known Venus for thousands of years. The ancient Romans named it after their goddess Venus, goddess of love and beauty.

Venus is the brightest thing in the night sky except for the Moon. It is sometimes called the morning star or the evening star as at some elongations it is easily seen just before the sun comes up in the morning. At other times, it can be seen just after the sun goes down in the evening. Venus comes closer to the Earth than any other planet does.

Venus is sometimes called the sister planet of Earth as they are quite similar in size and gravity. In other ways the planets are very different. Venus' atmosphere (air) is mostly carbon dioxide with clouds of sulphuric acid. Sulphuric acid is a chemical that is poisonous to life. For this it is sometimes known as the Earth's "evil twin".

The thick atmosphere makes it hard to see the surface. Until the late twentieth century many thought there might be life there. The pressure on Venus' surface is 92 times that of Earth. Venus has no moons. Venus spins very slowly on its axis and it spins in the opposite direction to the other planets.

Venus is a terrestrial planet so, like the Earth, its surface is made of rock. Venus is much hotter than Earth. All the carbon dioxide in the atmosphere acts like a blanket, trapping heat from the Sun. This effect is called the greenhouse effect and it is very strong on Venus. This makes the surface of Venus the hottest of any planet's surface in the Solar System with an estimated average temperature of 480 °C (896.0 °F). This is hot enough to melt lead or zinc.

Venus has no oceans because it is much too hot for water. Venus' surface is a dry desert. Because of the clouds, only radar can map the surface. It is about 80% smooth, rocky plains, made mostly of basalt. Two higher areas called continents make up the north and south of the planet. The north is called Ishtar Terra and the south is called Aphrodite Terra. They are named after the Babylonian and Greek goddesses of love.

The surface of Venus looks like it has been shaped by volcanic activity. Venus has a lots of volcanoes. The surface of Venus is estimated to be 300–600 million years old.

Unlike Earth or Mars, Venus does not have defined highlands or lowlands, and it does not have tectonic plates.

Venus orbits the Sun at an average distance of about 108 million km (67 million mi). It completes an orbit every 224.7 days. The rotation of Venus is slow. A Venusian sidereal day is longer than a Venusian year.