Mercury, the Swiftest Planet





Mercury—the smallest planet in our solar system and nearest to the Sun—is only slightly larger than Earth's Moon. Its surface is covered in tens of thousands of impact craters.

From the surface of Mercury, the Sun would appear more than three times as large as it does when viewed from Earth, and the sunlight would be as much as 11 times brighter.

Despite its proximity to the Sun, Mercury is not the hottest planet in our solar system— that title belongs to nearby Venus, thanks to its dense atmosphere. But Mercury is the fastest planet, zipping around the Sun every 88 Earth days. Mercury is appropriately named for the swiftest of the ancient Roman gods.









Quick facts about Mercury

Smallest
It is a little bigger than Earth's Moon


Inside Track
Mercury orbits closest to the Sun


Fast Times
A year on Mercury is 88 Earth days


Rough Surface
Mercury is cratered like the Moon


Bring a Spacesuit
Mercury has a thin exosphere


Moonless
Mercury has no moons


Ringless
Mercury has no rings


Tough Spot
Mercury can't support life as we know it


Wear Eye Protection
Sunlight is 11 times brighter on Mercury


Greatest Hit
The Caloris Basin is a Texas-sized impact site