About the image: A global map of Mercury's surface created from images obtained by NASA's MESSENGER spacecraft. The colors are not what the eye would see, but are related to compositional variations on the surface. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
On the Back
Mercury—the smallest planet in our solar system and nearest to the Sun—is only slightly larger than Earth's Moon.
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.