The Final Frontier



Type of Planet

Jupiter is a gas giant, meaning a giant planet composed mainly of hydrogen and helium.


The gas giant has no firm surface. Instead, the atmosphere of Jupiter essentially makes up the entire planet.

Jupiter is made up predominantly of hydrogen, which accounts for 90 percent of the atmosphere. Nearly 10 percent is composed of helium. The rest is made up of ammonia, sulfur, methane, and water vapor.

Jupiter is like a star in composition. If Jupiter had been about 80 times more massive, it would have become a star rather than a planet.

Towards the centre of Jupiter the hydrogen changes from a gas to a liquid. It can even become metallic.

The planet's surface is covered in thick red, brown, yellow and white clouds. The best known feature of Jupiter is the Great Red Spot, a storm that is larger than Earth.

Planetary Rings

Jupiter has three thin rings that are difficult to see. They are made up mostly of tiny dust particles.

Size (Diameter), Mass, and Density

Jupiter is the largest planet in the Solar System. Jupiter is so big that all the other planets in the solar system could fit inside it. Earth would fit inside Jupiter over 1,300 times.

Jupiter is over 300 times the mass of the Earth, and two and a half times the mass of all the other planets in the Solar System combined.

The density of Jupiter is 1.33 grams per cubic centimeter, compared to Earth's 5.51.


Jupiter is the largest and most massive planet in the Solar System, but being a gas giant, Jupiter is naturally less dense than Earth. As a result, Jupiter’s gravity is just 2.4 times that of Earth.

Magnetic Field

Jupiter has a large magnetic field, that at the tops of its clouds is 10 times stronger than the Earth's.

Jupiter's magnetic field is thought to be produced from electrical currents in its rapidly spinning metallic hydrogen interior.


The average temperature on Jupiter is a chilly -153 degrees celsius. The core temperature, however, may be about 24,000 degrees Celsius. That's hotter than the surface of the sun!

Length of a Day (Rotation)

Jupiter spins fastest of all the Solar System's planets. A day on Jupiter lasts only 9 hours 55 minutes.

As a gas giant, Jupiter does not rotate as a solid sphere. Jupiter's equator rotates slightly faster than its polar regions, making a day around 6 minutes shorter at the equator.

Axial Tilt

Jupiter, like Venus, has an axial tilt of only 3 degrees, so there is literally no difference between the seasons.

Length of a Year (Orbit)

A year on Jupiter lasts 11.86 Earth years.

Distance from the Sun

Jupiter is the fifth planet from the Sun at 483 million miles, and is usually the second brightest planet in the night sky, after Venus.