Gray planet Mercury with craters and rays of material ejected by impactors like asteroids.


Mercury is the closest planet to the Sun, and the smallest planet in our solar system - only slightly larger than Earth's Moon.

All about mercury

Within the light gray of Mercury's surface are splatters of pale blue, as the left side of the planet is in shadow.

It is a little bigger than Earth's Moon.

A near full-globe view of Mercury is seen in this image from NASA's Messenger spacecraft.

Mercury orbits closest to the Sun.

Color-enhanced view of Caloris Basin on Mercury

A year on Mercury is 88 Earth days.

Mercury - in 3-D!

Mercury is cratered like the Moon.


Mercury has a thin exosphere.


Mercury has no moons.

Gray-colored Mercury with bright ejecta visible in craters.

Mercury has no rings.

SSTP International Collaborations

Mercury can't support life as we know it.

Eruptions on the Sun resemble a grinning Halloween pumpkin

Sunlight is 11 times brighter on Mercury.

The Caloris Basin is a Texas-sized impact site.

Planet Mercury Overview

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.

Eyes on the Solar System lets you explore the planets, their moons, asteroids, comets and the spacecraft exploring them from 1950 to 2050.

Pop Culture

The smallest planet in our solar system has a big presence in our collective imagination. Scores of science fiction writers have been inspired by Mercury, including Isaac Asimov, C. S. Lewis, Ray Bradbury, Arthur C. Clarke, and H. P. Lovecraft. Television and film writers, too, have found the planet an ideal location for storytelling. In the 2007 film "Sunshine," the Icarus II spacecraft goes into orbit around Mercury to rendezvous with the Icarus I.

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