Mercury is the smallest planet in our solar system and the one closest to the Sun. Named after the Roman messenger god, it orbits the Sun at an average distance of about 36 million miles, completing a revolution in just 88 Earth days. Mercury's surface is marked by extensive cratering and extreme temperature variations, with scorching days and freezing nights. Despite its proximity to the Sun, Mercury has a very thin atmosphere, composed mostly of oxygen, sodium, and hydrogen. This enigmatic planet has intrigued astronomers for centuries, prompting numerous studies and several spacecraft missions, such as NASA's MESSENGER, to uncover its many secrets.