MESSENGER spacraft MESSENGER spacecraft Why Mercury? The Mission Education News Center Mission Operations Science Operations Who We Are Frequently Asked Questions MESSENGER Webcam Related Links Contacts Home
MESSENGER BannerThe NASA LogoThe Carnegie Institution of Washington LogoThe John Hopkins University Logo
bannerleft side of the Education and Public Outreach BannerRight side of the Education and Public Outreach BannerRight side of the Education and Public Outreach Banner

Mercury's Size

Mercury is the second smallest planet; only Pluto is smaller. Mercury’s diameter is 4879 km, while Earth’s is 12,756 km. In fact, Mercury is not much larger than our Moon, which has a diameter of 3475 km.

day on mercury animation

How do the planets size up? Check out the "Planet Size Comparison" animation. Click on the image above.

Previous FactNext Fact

The Elusive Planet banner
Fast Facts
History and Culture
Inside and Out
Around the Sun
 
The Fast Fact banner
How Far from the Sun is Mercury?
How Long is a Year on Mercury?
How Fast Does Mercury Spin?
How Long is a Day on Mercury?
How Big is Mercury?
What is Mercury's Mass?
How Much Would I Weigh on Mercury?
 
Odd but True... heading
The Sun’s diameter is 1.38 x 106 km, making it about 286 times larger than Mercury. So if you were to make a scale model of Mercury and the Sun, representing Mercury by a marble 1.0 cm across, the sphere representing the Sun would be 2.86 m in diameter!