Solar System

Jupiter is the majestic king of the Solar System and is the biggest planet. It is so enormous that it is bigger than the smallest stars and is 1300 times bigger than Earth!

It is also home to the largest storm in the Solar System. Called the Great Red Spot, this gigantic storm is twice as big as Earth and has been raging for 400 years.

                  Inside of Jupiter
        The inside of Jupiter. The core is rocky and is surrounded by ice. The large brown part is liquid hydrogen.
Image copyright CJ. Hamilton
The planet Jupiter as imaged by the Cassini probe. The large oval is a storm called the Great Red Spot.
Image copyright NASA/JPL
The inside of Jupiter is tumultuous and has a core that is 10 times the size of Earth. This is enveloped by a layer of liquid hydrogen. Jupiter's massively strong gravity squeezes the hydrogen until it becomes metallic. This in turn creates an electric current because the hydrogen rotates around the core either more quickly or slowly. The electric currents generate a massive magnetic field. Also since the gravity of Jupiter is very strong, it has been used to make space probes travel faster towards their target destinations. This is known as the slingshot effect and was used on the New Horizons probe launched in 2006, which is on its long journey to Pluto.  

Name: Jupiter

Distance from Sun: 483,682,810 miles

Diameter: 88 846 miles

Length of Day: 9 hours 56 minutes

Length of Year: 11.9 years

Number of moons: 79


Planet Jupiter is swathed in latitudinal light and dark bands and this suggests that they are made out of different materials. The light clouds are made out of pure frozen ammonia. The dark clouds are composed of an ammonia composite containing different chemicals.

The storms and other weather of Jupiter is caused by both the Sun's heat and also Jupiter's internal gravity. The weather of Jupiter includes superbolt lightning and polar aurorae which can be seen in the image below.

Aurorae on Jupiter

The ghostly glow of Jupiter's aurorae are visible at the north and south in this Hubble Space Telescope image.

Interestingly these aurorae can't be seen in visible light and are only visible in ultraviolet light. This image was created by blending the ultraviolet images of Jupiter with the visible light images.

Aurorae are created when charged particles from the Sun hit the magnetic field. This causes hydrogen particles in the atmosphere to glow. The charged particles might also have come from one of Jupiter's moons, Io.

The brown colour of the clouds come from certain compounds called chromophores being exposed to ultraviolet radiation.

Image copyright NASA/ESA/Hubble Heritage Team (STSci/AURA)

Jupiter has a whopping 63 moons, which four of these were discovered in 1610 by Galileo Galilei. These moons are known as the Galilean moons and they are Europa, Ganymede, Io and Callisto.

The moon in the picture to the left is Callisto, which is icy. It is 2985 miles wide and 1.2 million miles away from Jupiter.

Ganymede is the largest moon in the Solar System, which is apt as it orbits the largest planet. Consequently it is bigger than Pluto and surprisingly Mercury as well and has a diameter of 3270 miles.

Half of Ganymede is ice and the other half is rock and metal.

The moon Callisto, which is one of the four largest moons.
Image copyright CJ. Hamilton

Io is a truly nightmarish hell of a moon and has about several hundred volcanoes. It is the second hottest object in the Solar System after the Sun and as an added bonus, the sulphuric lava is hundreds of degrees hotter than the lava on Earth.

The force behind Io's phenomenal heat is the gravity of Jupiter and the other large moons. This heats up the interior of Io and causes rock to liquify.

The moon Europa is made out of ice and there are hypothetical liquid oceans underneath the surface. It is the smallest of the Galilean moons and its name comes from the daughter of an ancient Phoenician king.

The surface is made out of ice and is covered in dark streaks that cover the whole surface. The origin of these streaks is unknown.

This moon is probably the likeliest candidate for extrasolar life that might live underneath the ice. It would be difficult for a space probe to drill through the ice and then survive while submerged in the ocean although it is possible in the future.

Strange surface of Europa Volcanic eruption on the moon Io
Tvashtar Catena, a volcanic caldera on the moon Io. The orange parts are lava from a volcanic eruption.
Image copyright NASA/University of Arizona
The ridged and pitted surface of Europa. The round spots are called lenticulae. This image was snapped by the Galileo probe, named after the discoverer of the Galilean moons.
Image copyright NASA/JPL/University of Arizona/
University of Colorado