![Gray planet Mercury with craters and rays of material ejected by impactors like asteroids.](https://cdn.statically.io/img/science.nasa.gov/wp-content/uploads/2023/05/mercury-from-messenger-pia15160-1920x640-1.jpg?w=4096&format=jpeg)
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.](https://cdn.statically.io/img/science.nasa.gov/wp-content/uploads/2017/10/pia15051-mercury.jpg?w=4096&format=jpeg&crop=1)
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.](https://cdn.statically.io/img/science.nasa.gov/wp-content/uploads/2023/09/True_Mercury.jpg?w=4096&format=jpeg&crop=1)
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.](https://cdn.statically.io/img/science.nasa.gov/wp-content/uploads/2023/07/messenger.jpg?w=4096&format=jpeg&crop=1)
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](https://cdn.statically.io/img/science.nasa.gov/wp-content/uploads/2023/09/spectra-mercury.jpg?w=4096&format=jpeg&crop=1)