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

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

Mercury is only slightly larger than Earth's Moon. Its surface is covered in tens of thousands of impact craters. 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.

Get the 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

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. The European Space Agency and JAXA launched a joint mission to Mercury in 2018. The mission, called BepiColombo, is made up of two spacecraft.

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 for 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.

Mercury

13 Images
Two overlapping views of Mercury. The first, on the left side of the frame shows the planet – with two-thirds of its right side lit up by sunlight – in gray, with very slight color variations, including the occasional beige tint to the gray, and bright, silvery white rays spreading across the ground, emanating from about a half-dozen craters. It’s partially covering the other view of Mercury against the black backdrop of space, behind and to the right of the first planet image. This is similarly lit, its right side two-thirds bathed in sunlight, but the surface is a riot of colors – yellows and oranges capping the north and south poles, craters appearing as bright golden yellow accented in turquoise rings and lines, vivid navy and electric blue covering much of the planet’s upper left and lower right quadrants, while an underlying smear of mauve covers the lower left to upper right.
On May 9, 2016, Mercury passed directly between the Sun and Earth, making a transit of the Sun. Mercury transits happen about 13 times each century. NASA SDO studies the Sun 24/7 and captured the eight-hour event.
Mercury
Mercury
Mercury
Part of the planet Mercury
Abedin crater on Mercury
Mercury from Messenger
Four colorful angles of Mercury using data from two MESSENGER instruments
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Learn More

  • Gray and white smiling,cartoon-like illustration of planet Mercury.

    For Kids: All About Mercury

    Facts about Mercury for kids.

  • A full globe view of gray-colored planet Mercury as seen from a spacecraft. Craters and white patches also are visible.

    NASA Photojournal: Mercury

    Images of Mercury from spacecraft.

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