Іо is one of the many moons of Jupiter, the largest planet in our solar system. It is known for its strikingly colorful surface, which is covered in sulfur and volcanic activity. This makes Іо the most geologically active body in the solar system, with hundreds of active volcanoes. Discovered by Galileo Galilei in 1610, Іо is the innermost of Jupiter's four largest moons, known as the Galilean moons. Its unique features and constant volcanic eruptions provide valuable insights into planetary geology and the dynamics of celestial bodies.