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

Mercury

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

Mercury Facts

The smallest planet in our solar system and nearest to the Sun, Mercury 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 seven times brighter.

More Mercury Facts
Gray-colored Mercury with bright ejecta visible in craters.
NASA's Mercury MESSENGER took this image of Mercury's southern hemisphere. The bright rayed crater near the limb is Debussy, named for the impressionist era French composer.
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

Because Mercury is so close to the Sun, it is hard to observe from Earth except during dawn or twilight.

The first spacecraft to visit Mercury was NASA's Mariner 10, which imaged about 45% of the surface. 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.

Learn 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 this page for a curated collection of resources about Mercury.

This resources page includes activities that can be done at home, as well as videos and animations, images, and printable graphics. This content is for educators, students, and anyone interested in learning more about Mercury!

Explore Resources About Mercury
Mercury in several different colors
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.
Keep Exploring

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