Mercury, the smallest and innermost planet in our solar system, orbits the Sun at an average distance of about 36 million miles (58 million kilometers). Its proximity to the Sun causes extreme temperature fluctuations, ranging from blistering daytime highs to freezing nighttime lows. With a diameter of roughly 4,880 kilometers, Mercury is only slightly larger than Earth’s moon and lacks a substantial atmosphere, leaving its surface vulnerable to the Sun’s intense radiation and meteoroid impacts.

The surface of Mercury is marked by vast plains, rugged mountains, and numerous impact craters, offering insights into the planet’s geological history. Its terrain features expansive plains resembling lunar maria and scarps caused by the planet’s shrinking due to cooling. Despite its proximity to Earth, Mercury remains a challenging planet to observe from Earth due to its proximity to the Sun and its elusive presence near the horizon during twilight.

Mercury’s orbit is eccentric, meaning it is not a perfect circle, and it completes a revolution around the Sun in about 88 Earth days. Due to its slow rotation and peculiar orbit, a day on Mercury (one rotation on its axis) is longer than its year (a revolution around the Sun), making it the only planet in the solar system with this characteristic. These unique properties make Mercury a fascinating subject for scientific study, providing valuable insights into the processes that shape terrestrial planets and the dynamics of our solar system.