Venus

Venus is the second planet from the Sun and the sixth largest planet in our Solar System. Due to its proximity to Earth it is the brightest planet in our night sky and so was discovered very early on. It appears brightest just after sunset and just before sunrise, and so is sometimes known as the “Evening Star” or the “Morning Star”. Venus is named after the Roman goddess of love and beauty.

It takes Venus 225 of our Earth days to complete one very regular orbit around the Sun. Venus itself rotates very slowly, so one day on Venus is about as long as 117 Earth days. Venus rotates in retrograde. This is the opposite direction of most planets including Earth, so from Venus the Sun would appear to rise in the west and set in the east. Venus has no satellites.

Venus is surrounded by a thick, toxic atmosphere consisting of mostly carbon dioxide. Clouds of sulphuric acid create an extreme greenhouse effect around the planet, and obscure its surface from view. The surface pressure of the atmosphere is very high, 90 times more than the Earth’s atmospheric pressure. The temperature on Venus is around 740 K (466°C), hot enough to melt lead.

Venus is very similar in size and structure to Earth. It is mostly a desert surface covered in thousands of mountains and volcanoes. Venus’ largest mountain, Maxwell Montes, is similar in size to Mount Everest on Earth. There is evidence that oceans existed on Venus, but the intense heat from the Sun caused them all to boil away. The lack of a magnetic field around Venus meant the hydrogen in the water could have been swept into space by solar wind.

More than 20 spacecraft have been to Venus, employing radar or infrared to map the surface of the planet through its thick clouds. In 1970 Venera 7 became the first spacecraft to land on another planet when it touched down on the surface of Venus. However, the extreme heat is difficult to endure for long periods of time, so only 23 minutes of data could be collected.