10 Jupiter Facts – Interesting Facts About the Planet Jupiter

Jupiter - The Fifth Planet (NASA)

Jupiter – The Fifth Planet (NASA)

Jupiter is the largest planet in our solar system and the fifth planet from the Sun, after Mercury, Venus, Earth, and Mars. It’s named for Jupiter, the Roman equivalent to the Greek’s Zeus, the king of the gods. Humans first recorded sighting this world in 7th or 8th century Babylonia.

Here are 10 interesting Jupiter facts, as well as essential data about this gas giant.

10 Jupiter Facts

  1. Jupiter is the largest and most massive planet in the Solar System. You would need to line up 11 Earths to reach Jupiter’s mean diameter of 139,322 km. It would take 318 Earths to equal Jupiter’s mass of 1.90 x 1027 kg. Jupiter is 2.5 times more massive than all the other planets combined. The volume of Jupiter is so great that 1300 Earths could fit inside it.
  2. Jupiter has three thin rings, although they are not nearly as spectacular as those of Saturn. It’s difficult to see Jupiter’s rings, even with telescopes. Astronomers believe the rings consist of material ejected by the Jovian (Jupiter’s) moon when they are struck by meteorites.
  3. A day on Jupiter is 9 hours and 55 minutes, giving it the shortest day of any planet in the Solar System. Because it spins so quickly on its axis, the planet appears flattened at the poles, with a bulge at the equator. It’s wider at its equator than it is is if measured from pole to pole.
  4. Although Jupiter is famous for its Red Spot, this is actually a gigantic storm that will eventually fade away. In fact, it’s dwindling more quickly than expected. The Red Spot has persisted for about 350 years. It was spotted by the Italian astronomer Giovanni Cassini in 1665.

    Fun Jupiter fact - If you had been around over 350 years ago, you wouldn't have seen the Red Spot because it didn't exist then. (Voyager 1, NASA/JPL)

    Fun Jupiter fact – If you had been around over 350 years ago, you wouldn’t have seen the Red Spot because it didn’t exist then. (Voyager 1, NASA/JPL)

  5.  Jupiter can’t become a star. If the planet gained more mass, its size would decrease because gravity would pull the planet in on itself, but there simply isn’t enough mass for the hydrogen and helium to start the fusion process. Scientists estimate Jupiter could gain 4 times its present mass and still be the same size. It would need to be at least 70-80 times more massive than it is now to have any chance of becoming a star.
  6. The clouds we see on Jupiter are only 50 km thick. There are at least two decks or layers of clouds, which consist of ammonia crystals and maybe ammonium hydrosulfide and water. Lightning has been spotted within the atmosphere. The orange and brown coloration is believed to come from the interaction between ultraviolet radiation and phosphorus and and sulfur compounds. Below the clouds, Jupiter consists of hydrogen and helium. There is a layer of metallic liquid hydrogen and perhaps a rocky core.
  7. Jupiter exerts a massive magnetic field. It’s 14 times stronger than that of the Earth. All that spinning hydrogen generates a huge electromagnetic field.
  8. Jupiter has a lot of moons. There are four major moons, called the Galilean Moons, which are (in order from Jupiter) Io, Europa, Ganymede, and Callisto. Ganymede is the largest moon in the solar system. At least 67 moons have been named, but there are probably over 200 moons orbiting Jupiter. Galileo’s discovery in 1610 of the four largest moons was mankind’s first proof celestial bodies orbited something other than the Earth.
  9. Jupiter is so large and bright that it’s visible with your naked eyes. Jupiter is the 4th brightest object in the Solar System, after the Sun, Moon, and Venus. The planet appears as a bright star in the sky, although you can see the bands of color and four Galilean Moons with good binoculars or a telescope.
  10. Jupiter emits more energy than it gets from the Sun. This world generates heat, which it radiates outward to its moons. Because of its magnetic field, telescopes can view the aurora on Jupiter.

Jupiter Planetary Data

Axial Tilt3.13° to orbit
Surface Gravity24.79 m/s or 2.528 g
Mean Orbital Distance7.78 x 108 km (It takes about 43 minutes for light from the Sun to reach Jupiter.)
Orbital Period (year)11.86 Earth years
Apparent Magnitude-1.6 to -2.94
Chemical Compositionabout 89.8% hydrogen, 10.2% helium, with traces of methane, ammonia, hydrogen deuteride, ethane, and water. The clouds contain ices of ammonia, water, and ammonium hydrosulfide

What If Jupiter Never Existed?

Most extraterrestrial solar systems have their large planets close to their suns, not like our solar system, where the gas giants are out beyond the smaller, rocky worlds like the Earth and Mars. Have you ever wondered what it would be like if Jupiter didn’t exist?