Return to Scale View
About News Create With Us
Return to Scale View

How big is Ganymede?

Ganymede is 5,300 kilometers

The Incredible Size of Ganymede

Have you ever wondered about the largest moon in our solar system? You might be surprised to learn that it’s not our beloved Moon, but a giant moon orbiting Jupiter named Ganymede. It’s not just the biggest moon in our neighborhood, but it’s also the largest object in the solar system without an atmosphere. But how big is Ganymede, really? Let’s dive in and explore!

Size Comparison

To understand the size of Ganymede, it’s helpful to compare it to objects we’re familiar with.

  • Ganymede is bigger than the planet Mercury! Even though Mercury is the smallest planet in our solar system, it’s still pretty astonishing that a moon outstrips a planet in size.
  • Ganymede has a diameter of about 5,268 kilometers. This makes it even larger than the dwarf planet Pluto.
  • Ganymede is about 2.02 times the size of our Moon. Imagine if our night sky was dominated by a moon twice the size of our current one!

Its Exceptional Features

Ganymede’s large size allows it to host some unique features.

  • Ganymede is the only moon in the solar system that has its own magnetic field. This is a property usually associated with planets, not moons. - Ganymede is composed of equal amounts of silicate rock and water. It even has an internal ocean that may contain more water than all of Earth’s oceans combined. - Its surface is a mix of two main types of terrain. The darker regions are saturated with impact craters and are about four billion years old. The lighter regions, filled with extensive grooves and ridges, cover the rest of Ganymede.

Orbiting Jupiter

Ganymede may be a giant among moons, but it still has to follow the rules of gravity. It orbits Jupiter, the largest planet in our solar system, every seven days. Ganymede also shares a unique relationship with two other Jovian moons, Europa and Io. They are in a 1:2:4 orbital resonance, which means for every orbit Ganymede completes, Europa orbits twice and Io orbits four times.

A Moon with Planet-like Qualities

Ganymede is a fascinating object in our solar system. Its enormous size sets it apart from other moons, and its unique features make it more similar to a planet than a typical moon. Yet, despite its size and extraordinary traits, Ganymede silently orbits Jupiter, reminding us that there are still many wonders in our solar system waiting to be explored. So, the next time you look up at the night sky, remember Ganymede - the moon that’s more like a planet, the moon that’s bigger than Mercury, and the largest moon in our solar system. It’s a wonderful, giant mystery just waiting to be discovered.

Smaller By Category
Titan
Titan is Saturn's only large moon. It has a very thick atmosphere, which is mostly made up of nitrogen. Earth's atmosphere is also mostly nitrogen. Titan has seas of liquid methane. (It's around -180 °C.) There's even a continent called "Xanadu".
Mercury
Mercury is the closest planet to the Sun. It has no atmosphere. During the day, temperatures reach 430 °C, but at night, the temperatures fall to -180 °C. One Mercurian year is 88 Earth days.
Callisto
Callisto is the most distant of the Galilean moons. It orbits outside all the other Galilean moons and has the most meteor impact craters of them all.
Larger By Category
Mars
Mars is known as the Red Planet. It is red because it is rusty. Many people believe water and life once existed on Mars. However, even if that is true, the life wouldn't be like the little green men of sci-fi stories.
Asia
Asia is the Earth's largest continent, holding over four billion people – over half of the world's population. Africa is the second most populous continent, but only has one billion people.
Sirius B
Sirius B is a white dwarf. It's barely bigger than the Earth! It's usually pretty hard to see because it is hidden by Sirius A's blinding light. Sirius B is known as "The Pup".