Jupiter Facts

Jupiter Planet Profile

Distance from Sun: 483.8 million mi
Radius: 43,441 mi
Polar Diameter: 133,709 km
Orbital period: 12 years
Mass: 1.90 × 10^27 kg (318 Earths)
Length of day: 0d 9h 56m
Surface area: 23.71 billion mi²
Effective Temperature: -148 °C
Moons: 79, including (Io, Europa, Ganymede & Callisto)
First Recorded: 7th-8th Century BCE by Babylonian astronomers

Jupiter is the fifth planet from the Sun and is the largest planet in our Solar System. It was named after the roman king of the gods and the name fits its size.

If you compare the size of Earth to Jupiter, we could fit eleven Earths lined up next to each other just to stretch from one side of Jupiter to the other side. It would take 317 Earths to equal Jupiter’s mass.

Jupiter’s Moons

Another interesting thing about Jupiter is that it has 79 confirmed moons!  These are divided up into three distinct groups:

Inner moons, those closest to Jupiter; Galilean moons, Galileo Galilei; and Outer moons, the smallest and most distant from Jupiter. Ganymede is the largest of Jupiter’s moons, and the largest moon in the entire Solar System.

The other large moons around Jupiter are Callisto, Io, and Europa. Ganymede is larger than Mercury.

Jupiter’s Atmosphere

Jupiter’s atmosphere is difficult to define, mainly because it is a gaseous outer zone that transitions into the planet’s liquid layer.

Scientists have designated that the atmospheric pressure on Jupiter’s “surface” is equal to 10 times that of the Earth at sea level.

The atmosphere is around 90% hydrogen and 10% helium, which is almost the same as that of the Sun. Due to this fact, it is believed that Jupiter could have been a star.


Storms on Jupiter are beyond huge. They develop on the boundaries of the lighter and darker horizontal bands.

The Great Red Spot is around 25,000 km across, which is large enough to hold two Earths, and has been raging for centuries.

Jupiter’s interior is made up of three regions: a rocky core with a mass of between 12-45 times the size of the Earth that is made-up of various elements.

The second region makes up most of Jupiter’s mass and it surrounds the core with a layer of liquid hydrogen that is electrically conductive.

The third region is made up of ordinary hydrogen with some helium traces and this transitions to the atmosphere of the planet.

It’s Hot

One of the unique features of Jupiter is that it gives off more energy than it gets from the Sun.

The reason for this is the fact that the planet is so huge and its large mass exerts a strong gravitational force on itself, compressing the whole planet.

It creates a large amount of heat that is then expunged into space.

How long is a Year

Jupiter is a bit more than five times the distance from the Earth to the Sun, however, one Jupiter year is around 4,333 Earth days in length.

Jupiter has a minimal axis and therefore it doesn’t experience seasons. The rotation of Jupiter is just under 10 hours, which is the shortest period of rotation in the Solar System.

This fast rotation creates a bulge near its equator making it appear less spherical. The other thing about the rotation is that different parts move at different speeds.

The reason for this is that Jupiter isn’t a solid body. An example is that its polar atmosphere rotates five minutes slower than at the equator.

Facts about Jupiter

  • Galileo’s discovery in 1610 of Jupiter’s 4 moons was the first time proof could be shown that celestial bodies orbited something other than Earth and provided evidence of the Sun-centered Solar System model that Copernicus had discovered.
  • Jupiter does have a very faint ring system that is mainly made up of dust particles from various comet and asteroid impacts on its moons.
  • Jupiter’s magnetic field is nearly 14 times stronger than the Earth’s magnetic field.
  • Jupiter is one of only five planets that can be viewed by the naked eye and is the fourth brightest object in our Solar System.
  • We have had 9 spacecraft visits to Jupiter (so far), with only the Galileo mission being the single one designed to orbit the planet and study its moons.
  • The only thing that held Jupiter back from becoming a star was that it needed to be 80 times more massive.

Jupiter Quiz

  • Astronomy for Kids