Mercury is the smallest planet in our solar system. Simply put, it’s a little bigger than Earth’s Moon. It is the closest planet to the Sun, but it is not really the warmest. Venus is the warmest.

Along with Venus, Earth and Mars, it is one of the rocky planets. It has a solid surface that is covered with craters. It has a thin atmosphere and no moon. Mercury likes to simplify things.

This small planet spins slowly compared to Earth, so a day lasts a long time; it takes 59 Earth days to make one complete rotation. A year on Mercury goes by fast. Because it is the closest planet to the Sun, it does not take long to cover the entire circumference. It completes one lap around the Sun in only 88 Earth days. If you lived on Mercury, you’d have a birthday party every three months!

A day on Mercury is not like a day here on Earth. For us, the Sun rises and sets every day. Because Mercury rotates slowly and has a short year, it takes a long time for the Sun to rise and set there. This planet only has one sunrise every 180 Earth days. Doesn’t that seem weird to you?

Structure and surface

• It is the smallest planet in our solar system.
• It is a terrestrial planet: it is small and rocky.
• It has a thin atmosphere.

The weather on Mercury

• Its day lasts 59 Earth days.
• Its year lasts 88 terrestrial days.

Mercury’s neighbors

• It has no moons.
• It is the closest planet to the Sun.
• It has Venus as a neighboring planet.

Brief History

• It has been known since ancient times, since it is visible without the use of advanced telescopes.
• It has been visited by two spacecraft: Mariner 10 and MESSENGER.

What does Mercury look like?

Here you can see that Mercury is a light gray color.

This is the northern horizon as seen by the MESSENGER spacecraft during its third flyby.

The large, star-shaped crater toward the bottom of the sphere is called Debussy.

Colors have been added to the photograph so that you can better see the variations and craters on the surface.