Mercurio is the smallest planet in our solar system and the closest to the Sun. It has a rocky surface and is known for its extreme temperature variations, ranging from very hot during the day to extremely cold at night. Despite its small size, Mercurio has a significant magnetic field, which is unusual for a planet of its size. It takes about 88 Earth days to complete one orbit around the Sun, and a day on Mercurio lasts about 59 Earth days.