Mercury

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

Mercury Facts

Mercury is the smallest planet in our solar system and the nearest to the Sun.

Mercury is only slightly larger than Earth's Moon. It's the fastest planet, zipping around the Sun every 88 Earth days. Mercury is named for the swiftest of the ancient Roman gods.

Get the Facts

Gray-colored Mercury with bright ejecta visible in craters.

NASA's Mercury MESSENGER took this image of Mercury's southern hemisphere.

NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Mercury By The Numbers

How big is Mercury? How far is it from the Sun?

Use this tool to compare Mercury to Earth, and other planets.

Analyze and Compare

A gray, cratered world in the blackness of space, with about two-thirds of the planet illuminated by sunlight coming from the right. The overall gray shows some tan tints in some areas, and several craters have slivery-white rays extending outward from them, across the surface.

NASA's MESSENGER spacecraft captured a part of Mercury not previously seen by spacecraft after its closest approach to the planet on Jan. 14, 2008.

NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie

Exploring Mercury

The first spacecraft to visit Mercury was NASA's Mariner 10.

NASA's MESSENGER spacecraft flew by Mercury three times, and orbited the planet for four years before crashing on its surface at the end of its mission.

More About Mercury Missions

An illustration of the MESSENGER spacecraft at Mercury.

NASA's MESSENGER spacecraft is shown near Mercury in this illustration.

NASA

Mercury Resources

Explore a curated collection of resources about Mercury.

These resources include activities that can be done at home, as well as videos and animations, images, and printable graphics.

Explore Resources for Mercury

This image from NASA's MESSENGER spacecraft uses spectral data to highlight various minerals, features and properties on Mercury.

NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

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

Learn More

For Kids: All About Mercury
Facts about Mercury for kids.
Mercury Resource Package
Activities that can be done at home as well as videos, animations, printable graphics, and podcasts.
NASA Photojournal: Mercury
Images of Mercury from spacecraft.