Jupiter Explained: The Mind-Blowing Facts

~9 min
Jupiter Explained: The Mind-Blowing Facts

Jupiter is one of the brightest planets in our skies and the largest and most massive planet in the Solar System. It has faint rings, numerous moons, and an unstable surface. Is there something else? We made an overview of Jupiter and gathered all the mind-blowing facts about this vast planet. Enjoy!

Contents

Jupiter Planet Facts

  • Planet type: gas giant
  • Radius: 69,911 km (43,441 mi)
  • Mass: 1.8982×10^27 kg
  • Aphelion: 817 mln km (508 mln mi)
  • Perihelion: 741 mln km (460 mln mi)
  • Average distance from the Earth: 778 mln km (484 mln mi)
  • Surface temperature: −145 ℃ (−234 °F)
  • Solar day length: 9 h 55 m 33 s
  • Sidereal day length: 9 h 55 m 30 s
  • Year length: 11.8618 Earth years
  • Age: 4.603 billion years
  • Named after: Roman god of the sky and thunder

How big is Jupiter?

Jupiter is considered the giant or the Jovian planet, together with Saturn, Uranus, and Neptune. When ancient astronomers named Jupiter after the Roman ruler of all gods, they had no idea about its enormous size surpassing other planets. Yet, they came up with a very fitting name.

Jupiter's size

With a radius of 69,911 km (43,441 mi), Jupiter is the biggest planet in the Solar System. In comparison, the second-biggest Saturn has a radius of 58,232 km (36,184 mi). Jupiter is also the most massive planet — it’s more than twice as massive as all the other planets combined.

How many Earths can fit in Jupiter?

Are you struggling to imagine something as huge as Jupiter? Let’s say that it would take more than 1,300 Earths to build a single Jupiter. If the gas giant were the size of a basketball, the Earth would be the size of a grape.

Jupiter's orbit and rotation

Each planet takes a certain amount of time to complete one orbit around the Sun and one rotation around its axis. As we live on the Earth, we take the local days (24 hours) and years (365.25 days) as a standard. Let's see how different from our planet Jupiter is.

How long is a day on Jupiter?

Despite being the largest planet, Jupiter is also the fastest spinning planet in the Solar System; therefore, it has the shortest days. One day on Jupiter takes slightly less than 10 hours — the exact time varies from 9 hours and 56 minutes around the poles to 9 hours and 50 minutes close to the equator. The reason behind this difference is that Jupiter is a gas planet and doesn’t rotate as a solid sphere. Instead, its equator rotates slightly faster than the polar regions, which leads to the distinction in the day length in different areas.

How long is a year on Jupiter?

One Jovian year takes 11.8618 Earth years or 4,332.59 Earth days. In comparison, the second-largest planet Saturn has an orbital period of around 29 Earth years and the smallest Mercury revolves around the Sun every 88 Earth days.

How far away is Jupiter?

Jupiter is the fifth planet from the Sun: Mercury, Venus, the Earth, and Mars lie in between them. There is also the asteroid belt located roughly midway Mars and Jupiter’s orbits.

How far is Jupiter from the Sun?

The gas giant is 5.2 AU from the Sun or 778 mln km (484 mln mi) away. In comparison, Mercury, the closest planet to the Sun, is 0.4 AU or roughly 58 mln km away (35 mln mi) from our star. Quick reminder: one astronomical unit (AU) is the distance between the Sun and the Earth.

How far is Jupiter from the Earth?

The distance between planets is constantly changing because they are moving along their orbits. Jupiter is only 588 mln km (365 mln mi) away when it’s closest to our planet and 968 mln km (601 mln mi) at its farthest.

How long does it take to get to Jupiter?

If you want to make a simple flyby, it will take about 550-650 days as it happened with the Voyager spacecraft: Voyager 1 took only 546 days, and Voyager 2 took 688 days. However, if you’re actually planning to go into Jupiter’s orbit, you’ll need to be going slowly enough when you reach the planet. For example, NASA’s Galileo spacecraft flight duration was 2,242 days before it finally arrived at Jupiter.

What is Jupiter made of?

Jupiter doesn’t have a solid surface; its atmosphere just gets denser the farther down you go, transitioning into a liquid layer surrounding a small core. Simply, it means that the atmosphere of Jupiter makes up almost the entire planet. Jupiter (and its atmosphere) consists of about 90 % hydrogen and 10 % helium — which is very similar to the Sun’s composition.

Jupiter’s formation

Like other planets in the Solar System, Jupiter formed about 4.5 billion years ago, when gravity pulled gas and dust together to create the gas giant. The planet took most of the mass left over after the formation of the Sun and became more than twice the combined material of the other bodies in the Solar System. About 4 billion years ago, Jupiter settled into its current position as the fifth planet from the Sun.

Jupiter's structure

We still don’t know for sure what Jupiter’s core looks like. It might consist of solid materials or be a thick, boiling, dense soup. What we know is that the core is surrounded by a layer of liquid metallic hydrogen that extends out to 90% of the planet’s diameter.

Jupiter's surface

This gas giant doesn’t have the hard surface as we do on the Earth. The planet is mostly swirling gases and liquids. A spacecraft can’t land on it or fly through the planet due to the extreme pressures and temperatures that will crush, melt, and vaporize it.

What is the Great Red Spot on Jupiter?

The Great Red Spot is a giant storm about twice as wide as the Earth located in Jupiter’s Southern Hemisphere. It consists of crimson-colored clouds that spin counterclockwise at a speed that exceeds any storm’s speed on the Earth.

This storm was first observed in 1878; however, Gian Domenico Cassini in 1665 mentioned “Permanent Storm,” which is believed to be the Great Red Spot. Such a long-lasting storm can be explained by the absence of a solid surface on Jupiter. On the Earth, hurricanes disintegrate when they reach solid ground, but the Red Spot simply doesn’t have land to collide with.

However, the Great Red Spot has been shrinking over the years: from a length of about 40,000 km (24,850 mi) in 1879 to nearly 15,000 km (9,320 mi) in 2021. The reasons behind it are unknown.

Jupiter's moons

Jupiter and its numerous satellites resemble a miniature Solar System and present a scientific interest for astronomers around the world.

How many moons does Jupiter have?

Jupiter has 79 moons: 53 of them are named, and 26 are waiting for an official name. Most of them are small — about 60 satellites are less than 10 km (6.2 mi) in diameter. The number of moons is constantly changing; in 2003, astronomers discovered 23 new moons, then, in 2018, 12 more Jovian moons were found. As of 2021, Jupiter is losing to Saturn on the number of satellites; according to NASA, the ringed planet has 82 moons.

What are Jupiter's 4 largest moons?

Jupiter’s four largest moons are Io, Europa, Ganymede, and Callisto. They’re called the Galilean satellites after their discoverer and are as remarkable as Jupiter itself.

The largest one, Ganymede, is bigger than Mercury and is known as the most gigantic satellite in the Solar System. It even has its own magnetic field! Europa, in its turn, has a very high potential to be habitable — there is evidence of a vast ocean just beneath its icy surface. It’s thought to have twice as much water as the Earth. Io is the most volcanically active body in the Solar System, with hundreds of volcanoes on it.

Callisto, which is about the same size as Mercury (99% of its diameter, to be precise), is the third-largest satellite in our Solar System and may look boring against the background of the other three moons. However, in the 1990s, NASA’s Galileo spacecraft revealed that there might be a salty ocean beneath Callisto’s surface.

Jupiter's rings

The Jovian ring system was the third ring system discovered in the Solar System, after those of Saturn and Uranus. Jupiter’s rings are faint and mostly consist of dust; they’re likely leftovers from meteor bombardment of Jovian moons.

How many rings does Jupiter have?

Jupiter has four rings: the closest to the planet faint halo ring, a relatively bright but very thin main ring, and two wide and thick gossamer rings — the Amalthea and the Thebe. The last two are named after the moons of whose material they consist. You can take a closer look at the Jovian ring system mosaic to understand the Jovian ring system better.

Are Jupiter's rings visible?

You surely won’t see the Jupiter rings with the naked eye since they’re too faint and tenuous. For ground-based observation, the largest telescopes available are required. Even from space, they’re visible only when viewed from behind Jupiter and are lit by the Sun or directly viewed in the infrared.

Missions to Jupiter

Since 1973, nine spacecraft have visited Jupiter. Let’s talk about the most noteworthy ones.

The first one was NASA’s Pioneer 10 that provided hundreds of Jupiter’s photos and collected some measurements. The Pioneer 11 in 1974 got three times closer to the planet than its predecessor.

In 1979, the famous Voyager spacecraft discovered the Jovian ring system and took thousands of pictures of clouds and storms on the planet. Those pictures also showed that the mysterious Great Red Spot is a gigantic storm. Moreover, Voyager 1 and 2 discovered dozens of volcanoes on Jupiter’s moon Io — the first found active volcanoes on another space object.

NASA’s Galileo probe became the first spacecraft to enter Jupiter’s orbit; it arrived on the planet in 1995. The Galileo mission, among many other things, examined Jupiter’s atmosphere and immense magnetic field and closely studied the Galilean moons. Several years later, in 2000, the Cassini spacecraft that was heading to Saturn took some of the best photos we have of Jupiter.

The second spacecraft ever to enter Jupiter’s orbit is called Juno. It arrived at Jupiter in 2016 and will be exploring the gas giant until September 2025 or the spacecraft's end of life.

Upcoming Events

Learn about the future events that will occur with Jupiter in the sky.

August 20: Jupiter at opposition

On August 20, 2021, at 00:00 GMT (August 19, 8:00 p.m. EDT), Jupiter will reach an opposition. In other words, the Earth will fly between the gas giant and the Sun, which means that Jupiter will be opposite to the Sun in our skies. For observers from the Earth, the time around opposition is perfect for viewing the planet — it will appear at its biggest and brightest. By the way, only five hours later, at 5:00 GMT (01:00 a.m. EDT), the planet will come to its closest point to the Earth.

Don’t be discouraged if you miss the night of opposition! It only marks the middle of the best observation time, so you’ll have a couple more weeks — spot Jupiter in the sky with the help of our astronomy apps.

October 18: Jupiter ends retrograde motion

On October 18, 2021, at 5:13 GMT (1:13 a.m. EDT), Jupiter will return to its usual westward movement ending its retrograde motion. On this night, the planet will be placed in the constellation Capricornus and shine with an apparent magnitude of -2.6.

F.A.Q.

What color is Jupiter?

Jupiter is a beautifully colored planet covered with mainly white, orange, brown, and red clouds; the Great Red Spot has a reddish-brown color.

Who discovered Jupiter?

Jupiter was known from ancient times, but the first person who provided detailed observations was Galileo Galilei in 1610.

What does Jupiter look like?

Jupiter is a gas giant covered with swirling cloud stripes. It looks like a very bright dot to the naked eye in our skies, and a small telescope will show it as a pale white or cream color planet.

Can humans live on Jupiter?

Well, landing on Jupiter is a bad idea for human beings. The word “land” itself isn’t very appropriate since there is no solid land on Jupiter. You would fall inside the planet until you reach its core, experiencing a thousand times stronger pressure than on the Earth on the way.

What is between Mars and Jupiter?

There is the asteroid belt between the orbits of Mars and Jupiter. This donut-shaped region contains solid, irregularly shaped bodies of different sizes and shapes called asteroids and minor planets.

Where is Jupiter in the sky?

The easiest way to find Jupiter in the sky is to use stargazing apps. Open the search field, type in “Jupiter,” and tap the corresponding result. An app will show you the planet’s position in the sky.

Did you know?

  • Jupiter has no seasons due to a very small tilt of only 3 degrees. Instead, there are a lot of long-term storms on the gas giant planet.
  • Jupiter is a failed star. It would need more than 70 times its current mass to start a nuclear fusion process and become a real star.
  • Jupiter has the largest ocean in the Solar System — it’s made of hydrogen instead of water.
  • Jupiter has the strongest magnetic field of any planet in the Solar System.

And this was everything about Jupiter — from its size to exploration missions. Share the article on social media and watch our cartoon about the gas giant that explains facts about Jupiter in simple words.

Wishing you clear skies and happy observations!