The Mercury

The Mercury

 Mercury is one of the four rocky planets in the solar system. In terms of size, it is the smallest planet. Its diameter is 4,879 km. A year there lasts 88. One day on Mercury lasts 58 days 15 hours and 30 minutes on Earth. Despite its small size, it is a very dense planet. Each cubic centimetre has a density of 5.4 g, only the Earth has a higher density. This is largely due to the fact that Mercury is composed mainly of heavy metals and rocks. Due to its proximity to the Sun, it is difficult to study. During 1974 and 1975, Mariner 10 passed through Mercury's surface three times and in that time mapped almost half of the planet's surface. On August 3, 2004, the Messenger spacecraft was launched from Cape Canaveral Air Station and was the first spacecraft to visit this planet since the mid-1970s. The planet was named after the Roman messenger of the gods. The exact date of Mercury's discovery is unknown. The first historical mention comes from the Sumerians, around 3000 BC.