Unlike planet Earth, planet Mercury doesn’t have a moon. But looking from Earth, Mercury resembles earth’s moon. Just like our moon, Mercury’s surface has many cliffs and craters. In the beginning, Earth, Mars, and Venus had craters as well. These craters were created due to impacts from incoming solar system debris during a period called the “Late Heavy Bombardment,” which ended about 3.8 billion years ago. Unlike Earth, Mercury lacks any substantial atmosphere to erode those craters so it remains the most heavily cratered planet in our solar system.