What is the diameter of the planet Mercury?

The diameter of Mercury is 3,032 miles, making it the smallest planet in the solar system. Earth's moon has a diameter of 2,159 miles, so Mercury isn't much larger than the moon.

Mercury has been shrinking since it formed billions of years ago, and scientists believe the cooling of Mercury's core has caused the rocky terrain to contract over the years. Since Mercury is a fairly small planet, it is less dense than Earth, which means it has a smaller gravitational pull. Objects and people on Mercury would weigh 62 percent less than they do on Earth, and a person could jump 2.6 times higher on Mercury.