Jupiter – King of Solar System

Jupiter is the king of our solar system. It’s the fifth planet from the Sun and by far the largest, boasting a mass over two and a half times all the other planets combined. Made mostly of hydrogen and helium gas, Jupiter is a swirling giant with a colorful atmosphere and a fascinating Great Red Spot, a giant anticyclonic storm.

Jupiter’s immense gravity can deflect asteroids and comets. It acts like a giant cosmic vacuum cleaner, sometimes pulling objects into its orbit or slinging them out of the solar system altogether.

Some scientists believe that Jupiter is a “failed star”. Jupiter and stars share a similar basic composition, primarily hydrogen and helium. Stars ignite when their mass reaches a critical point, allowing them to fuse hydrogen in their cores, releasing immense energy. Jupiter is massive, but not quite massive enough to achieve this sustained nuclear fusion.

This suggests that during the formation of our solar system, Jupiter might have accumulated slightly more mass, potentially reaching a point where it could have initiated limited hydrogen fusion for a brief period. However, it lacked the critical mass to sustain this fusion and become a full-fledged star.

Most astronomers believe Jupiter formed alongside the Sun from the same collapsing cloud of gas and dust. Due to its position in the solar system and the way the material coalesced, it accumulated a large amount of gas but not enough to trigger sustained nuclear fusion.

It’s important to remember that Jupiter wasn’t a star that somehow shrunk or lost mass. It’s more accurate to say it never quite reached the necessary mass threshold to become a star in the first place.

What is the Size of Jupiter?

Jupiter’s radius is 69,911 kilometers (43,441 miles). Jupiter’s diameter is 139,822 kilometers (86,881 miles). Jupiter’s circumference is 439,264 kilometers (273,865 miles). This makes it 11 times wider than Earth.

What is the Mass and Volume of Jupiter?

Jupiter boasts a mass of approximately 1.898 × 10^27 kilograms and its volume is approximately 1.43 x 10^15 cubic kilometers (km³). Due to its immense size, Jupiter holds a staggering volume of 1,321 times that of Earth. You can fit over 1,300 Earths inside Jupiter.

What is the Temperature of Jupiter?

Jupiter’s average temperature is minus 234 degrees Fahrenheit (minus 145 degrees Celsius), making it cold even in its hottest weather.

What is Jupiter’s Average Distance from the Sun & Earth?

In terms of its distance from the Sun, Jupiter orbits at an average distance of about 778 million kilometers (483 million miles). Jupiter’s average distance from Earth is about 628.7 million kilometers (about 389.5 million miles).

How long does it take Jupiter to Orbit the Sun?

It takes Jupiter approximately 11.86 Earth years to complete one full orbit around the Sun. This means a single “year” on Jupiter is much longer than a year on Earth.

How long does it take Jupiter to Spin on its Axis?

It takes Jupiter only about 9.9 hours to complete one full rotation on its axis. This is also known as Jovian Day. Jupiter’s rapid spin contributes to its oblate shape, bulging slightly at the equator due to the centrifugal force.

Gravitational Field Strength:

The surface gravity of Jupiter is approximately 24.79 m/s² (meters per second squared). This is roughly 2.5 times stronger than Earth’s surface gravity (which is 9.81 m/s²).

Escape Velocity:

The escape velocity required to leave the gravitational pull of Jupiter is approximately 59.5 kilometers per second (km/s).

Moons of Jupiter:

Jupiter has more than 95 moons This incredible family can be broadly divided into two groups.

Inner Moons: 

These are smaller moons, typically less than 300 kilometers across, residing close to Jupiter. They play a crucial role in shaping and maintaining the intricate structures within Jupiter’s faint rings.

Outer Moons: 

This group comprises the larger and more fascinating moons of Jupiter. Here are a few highlights:

The Galilean Moons:

These four moons, Io, Europa, Ganymede, and Callisto, were the first discovered beyond Earth’s moon. Each holds immense scientific interest:

  • Io: 

The most volcanically active body in our solar system, spewing sulfurous plumes.

  • Europa: 

A moon with a vast subsurface ocean, potentially harboring conditions suitable for life.

  • Ganymede: 

Ganymede is the largest moon in our solar system, even bigger than Mercury.

  • Callisto: 

Covered in a heavily cratered icy surface, hinting at a long and violent past.

What is the Composition of Jupiter?

Jupiter is a gas giant. This means it lacks a well-defined surface and is primarily composed of hydrogen, the lightest and most abundant element in the universe. Hydrogen makes up a staggering 96% of Jupiter’s mass.

The remaining 4% is a blend of helium, methane, ammonia, water vapor, and trace amounts of other elements. This composition gives Jupiter a vibrant atmosphere, showcasing yellows and browns attributed to ammonia crystals and phosphorous respectively.

What is the Interior Structure of Jupiter?

Hidden beneath the swirling clouds lies a complex and dynamic interior structure that scientists are still actively piecing together. Due to the immense pressure and scorching temperatures within Jupiter, direct exploration with probes is currently impossible.

However, sophisticated models and data from spacecraft missions like Galileo and Juno provide valuable insights.

The Core:

At the heart of Jupiter lies a core estimated to be 9-10 times the Earth’s mass. Scientists believe this core is primarily composed of iron and nickel, surrounded by a layer of molten rock and icy compounds compressed by the immense pressure.

Metallic Hydrogen:

Moving outwards, we encounter a layer of metallic hydrogen. Under the immense pressure within Jupiter, hydrogen gas transforms into a liquid conductor of electricity. This layer is believed to be responsible for generating Jupiter’s magnetic field, which is weaker than Earth’s but significantly stronger due to the planet’s larger size.

A Vast Ocean:

Above the metallic hydrogen lies a vast ocean of liquid hydrogen and helium, gradually transitioning into a gaseous atmosphere as we reach higher altitudes. This layer is estimated to be tens of thousands of kilometers thick, containing more hydrogen and helium than all the stars in our galaxy combined.

What does the Atmosphere of Jupiter consist of?

Unlike Earth with its well-defined layers, Jupiter, the king of planets, boasts a more complex atmospheric structure. Here’s a breakdown of the prominent layers in Jupiter’s atmosphere:


The lowest and densest layer, accounting for about 80-90% of Jupiter’s atmosphere. This turbulent region is where most weather phenomena on Jupiter occur, including powerful storms, like the Great Red Spot, and swirling anticyclones.

Temperatures in the troposphere decrease with increasing altitude, reaching around -140°C (-220°F) at the tropopause (the boundary between the troposphere and stratosphere).


A relatively thin layer compared to the troposphere, located above the tropopause. Temperatures in the stratosphere actually start to increase with altitude due to the absorption of ultraviolet radiation by ozone. This is in contrast to Earth’s stratosphere where temperatures decrease.

The stratosphere plays a crucial role in shielding the lower atmosphere from harmful solar radiation.


The uppermost layer of Jupiter’s atmosphere, gradually thinning out into space.

Temperatures in the thermosphere soar due to the absorption of extreme ultraviolet and X-ray radiation from the Sun, reaching thousands of degrees Celsius. This hot, thin layer is responsible for the auroras that sometimes dance around Jupiter’s poles.


The outermost fringe of Jupiter’s atmosphere, where the gas particles are extremely sparse and begin to escape into space. The exosphere plays a role in the interaction between Jupiter and the solar wind, a stream of charged particles emanating from the Sun.

Jupiter’s atmosphere is primarily composed of hydrogen (H₂) and helium (He), similar to the Sun. However, it also contains trace amounts of other elements like methane (CH₄), ammonia (NH₃), and water vapor (H₂O). These trace gases are responsible for the color variations we see in Jupiter’s atmosphere.

What is Jupiter’s Magnetosphere?

Jupiter has the largest and strongest magnetosphere in the solar system. It is generated by the planet’s rapid rotation and metallic hydrogen core. Jupiter’s magnetosphere extends millions of kilometers into space and interacts with its moon Io, creating intense radiation belts.

Great Red Spot:

As we explore Jupiter’s atmosphere, one feature stands out, the Great Red Spot. This persistent anticyclonic storm, a giant swirling mass of red clouds, has been raging for centuries, possibly even millennia.

The exact cause of the Red Spot’s color and longevity remains a topic of investigation, with theories suggesting the role of upwelling gases and complex atmospheric interactions.

The Great Red Spot is a true giant. With an oval shape stretching roughly 16,000 kilometers (10,000 miles) across, it could easily engulf several Earths within its boundaries. Observations suggest its size has fluctuated over time, but it remains a dominant feature in Jupiter’s dynamic atmosphere.

Jupiter’s Formation:

Jupiter’s formation is believed to have occurred around 4.5 billion years ago, during the early stages of the solar system’s evolution. It is thought to have formed through a process known as core accretion, where a solid core of rock and ice gradually accumulated material from the surrounding protoplanetary disk.

As Jupiter’s core grew larger, its increasing gravitational pull attracted more gas and dust, particularly hydrogen and helium, which were abundant in the outer regions of the protoplanetary disk. This gas accretion phase led to the rapid growth of Jupiter’s atmosphere, eventually resulting in the formation of a gas-giant planet.

Jupiter’s massive size and powerful gravitational influence have played a significant role in shaping the architecture of the solar system, influencing the formation and orbits of other planets and celestial bodies. Its composition and structure hold valuable clues about the conditions and processes that prevailed during the early history of the solar system.

When and Who Discovered Jupiter?

Jupiter’s discovery is attributed to the Italian astronomer Galileo Galilei in 1610. Using a telescope he had built, Galileo observed four large moons orbiting Jupiter, now known as the Galilean moons (Io, Europa, Ganymede, and Callisto).

This discovery revolutionized our understanding of the solar system, as it provided evidence that not all celestial bodies orbited the Earth, as was commonly believed at the time.

Galileo’s observation of Jupiter and its moons played a pivotal role in the development of the heliocentric model of the solar system, which placed the Sun at the center with planets orbiting around it.

Jupiter’s Exploration:

Jupiter, the king of planets, has been a target for exploration since the days of Galileo Galilei’s first telescope observations in 1610. Pioneer spacecraft paved the way in the 1970s, revealing Jupiter’s immense size and gassy composition. The Voyager missions followed, providing stunning visuals of the swirling storms, the Great Red Spot, and the intricate dance of its moons.

Jupiter as compared to Saturn:

Jupiter Vs. Saturn

TypeGas GiantGas Giant
Average Distance from the Sun (AU)5.29.5
Diameter142,984 km (11.2 times Earth’s diameter)116,464 km (9.4 times Earth’s diameter)
Volume1,321 Earths764 Earths
Mass1.898 x 10^27 kg (318 times Earth’s mass)5.683 x 10^26 kg (95 times Earth’s mass)
Density1.33 g/cm³0.69 g/cm³ (less dense due to larger size)
AtmospherePrimarily Hydrogen (H2), Helium (He), with trace amounts of Methane (CH4), Ammonia (NH3), Water (H2O)Primarily Hydrogen (H2), Helium (He), with trace amounts of Methane (CH4), Ammonia (NH3), Water (H2O)
Great Red SpotA giant anticyclonic storm systemNo prominent persistent storm system like Jupiter’s Great Red Spot
RingsFainter, less extensive ring system composed primarily of dust and ice particlesExtensive, iconic ring system composed primarily of water ice and dust
Moons79 known moons (as of October 2023)82 known moons (as of October 2023)
Internal StructureMetallic hydrogen core, surrounded by a layer of liquid hydrogen and heliumMetallic hydrogen core, surrounded by a layer of liquid hydrogen and helium, with possible icy core


As we continue to explore Jupiter, his magnificent giant planet will continue to amaze our imaginations and inspire our quest for knowledge for years to come.

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