The Closest Planet to Our Sun Is Shrinking. Here’s What that Means - WKTV

Telltale wrinkles that cover Mercury, the closest planet to the sun, suggest it was once a larger world that has shrunk in size—and it may be shrinking more than scientists realized.

A mosaic of images taken by NASA's MESSENGER spacecraft shows impact craters on Mercury in October 2008.

Wrinkle ridges formed on Mercury as the interior of the planet cooled.

(CNN) — Telltale wrinkles that cover Mercury, the closest planet to the sun, suggest it was once a larger world that has shrunk in size—and it may be shrinking more than scientists realized.

The smallest planet in our solar system is about 36 million miles (58 million kilometers) from the sun on average and completes one orbit around our star every 88 days, according to NASA .