Jupiter Facts

All Jupiter Facts

Jupiter is the largest planet in the solar system, with a diameter of about 86,900 miles (139,800 km).
Jupiter is more massive than all the other planets in the solar system combined.
More than 1,300 Earths could fit inside the volume of Jupiter.
Jupiter is named after the king of the Roman gods, fitting for the largest planet in the sky.
In Greek mythology, Jupiter's counterpart is Zeus, ruler of the Olympian gods.
Jupiter spins faster than any other planet, completing a full rotation in under 10 hours.
Because it spins so fast, Jupiter bulges noticeably at its equator and is visibly flattened at its poles.
A year on Jupiter lasts about 12 Earth years, the time it takes to complete one orbit around the Sun.
Jupiter orbits the Sun at an average distance of about 484 million miles (778 million km).
Jupiter is often called a "gas giant" because it has no true solid surface to stand on.
Jupiter is made up almost entirely of hydrogen and helium, similar in composition to a small, dim star.
Deep inside Jupiter, immense pressure squeezes hydrogen into a strange liquid metallic state that conducts electricity.
Scientists believe the flow of liquid metallic hydrogen deep within Jupiter generates its extraordinarily powerful magnetic field.
Jupiter's magnetic field is the strongest of any planet in the solar system, roughly 20,000 times stronger than Earth's.
Jupiter's magnetosphere is so vast that, if it could be seen from Earth, it would appear larger than the full Moon in the sky.
Some scientists think Jupiter may have a dense core of rock and ice, though its exact size and structure are still debated.
Jupiter radiates more heat into space than it receives from the Sun, a leftover of the energy released during its formation.
Jupiter's Great Red Spot is a giant storm that has been raging for at least 150 years, and possibly far longer.
The Great Red Spot is large enough that Earth could comfortably fit inside it, though it has been slowly shrinking in recent decades.
Winds inside the Great Red Spot can reach speeds of over 250 miles per hour.
Nobody is entirely sure what gives the Great Red Spot its reddish color, though chemical reactions triggered by sunlight are a leading theory.
Jupiter's colorful bands of clouds are created by fast-moving jet streams flowing in opposite directions at different latitudes.
The lighter bands on Jupiter are called zones, and the darker bands are called belts, distinguished by differences in cloud height and composition.
Jupiter's clouds are made mostly of ammonia crystals, giving the planet its characteristic swirling white, orange, and brown patterns.
Jupiter has powerful storms and lightning far more intense than anything seen on Earth.
Jupiter has faint rings, first discovered by the Voyager 1 spacecraft in 1979, made mostly of fine dust rather than ice.
Jupiter's rings are thought to be made largely of dust kicked up by meteoroid impacts on its small inner moons.
Jupiter has the most confirmed moons of any planet in the solar system, with well over 90 discovered so far.
Jupiter's four largest moons, Io, Europa, Ganymede, and Callisto, are known as the Galilean moons.
The Galilean moons were discovered by Galileo Galilei in 1610, the first moons ever found orbiting a planet other than Earth.
Galileo's observations of Jupiter's moons helped confirm that not everything in the sky orbits the Earth, supporting the Copernican model of the solar system.
Ganymede, Jupiter's largest moon, is the biggest moon in the entire solar system, even bigger than the planet Mercury.
Ganymede is the only moon in the solar system known to generate its own magnetic field.
Europa, one of Jupiter's moons, is thought to hide a saltwater ocean beneath its icy crust that may hold more water than all of Earth's oceans combined.
Europa's icy surface is remarkably smooth, crisscrossed with long cracks that suggest an active, shifting shell of ice.
Europa's hidden ocean makes it one of the most promising places in the solar system to search for life beyond Earth.
Io, Jupiter's innermost large moon, is the most volcanically active body in the entire solar system.
Io's intense volcanism is driven by tidal heating, as Jupiter's gravity and the pull of neighboring moons constantly flex and stretch its interior.
Some of Io's volcanic plumes shoot material hundreds of miles above its surface.
Callisto, the outermost Galilean moon, has one of the most heavily cratered surfaces in the solar system, suggesting it hasn't changed much in billions of years.
Callisto may also hide a subsurface ocean beneath its ancient, ice-covered crust, though evidence is less certain than for Europa.
Many of Jupiter's smaller moons orbit backward relative to the planet's rotation, suggesting they were captured rather than formed alongside it.
Jupiter's powerful gravity acts like a cosmic shield, deflecting or capturing many comets and asteroids that might otherwise threaten the inner solar system.
In 1994, fragments of Comet Shoemaker-Levy 9 spectacularly collided with Jupiter, leaving dark scars visible in telescopes for months.
Jupiter shares its orbit with thousands of Trojan asteroids, clustered at gravitationally stable points ahead of and behind the planet.
Pioneer 10 became the first spacecraft to fly past Jupiter in 1973, offering humanity's first close-up look at the giant planet.
Pioneer 11 followed in 1974, using Jupiter's gravity to help slingshot itself onward toward Saturn.
Voyager 1 and Voyager 2 both flew past Jupiter in 1979, capturing detailed images of its moons and discovering its faint ring system.
NASA's Galileo spacecraft orbited Jupiter from 1995 to 2003, the first mission ever to orbit an outer planet.
Galileo dropped a small probe into Jupiter's atmosphere in 1995, which survived for about an hour before being crushed by extreme pressure.
At the end of its mission in 2003, the Galileo spacecraft was deliberately crashed into Jupiter to avoid contaminating potentially habitable moons like Europa.
NASA's Juno spacecraft has been orbiting Jupiter since 2016, studying its interior, atmosphere, and magnetic field in unprecedented detail.
Juno takes a highly elliptical orbit around Jupiter partly to minimize its exposure to the planet's intense radiation belts.
Juno's images revealed that Jupiter's poles are dotted with clusters of enormous, swirling cyclones arranged in striking geometric patterns.
NASA's Europa Clipper mission, launched in 2024, is designed to study Europa's icy shell and hidden ocean in detail during dozens of close flybys.
The European Space Agency's JUICE mission, launched in 2023, is headed to study Jupiter and its icy moons Ganymede, Callisto, and Europa.
JUICE is planned to eventually enter orbit around Ganymede, the first spacecraft ever to orbit a moon other than our own.
Jupiter's intense radiation belts are powerful enough to damage unshielded spacecraft electronics within hours.
Jupiter is bright enough to be one of the easiest planets to spot with the naked eye, often outshone in the night sky only by Venus.
With a small pair of binoculars, it's possible to spot Jupiter's four Galilean moons lined up beside the planet, just as Galileo once did.
Jupiter's average cloud-top temperature is a frigid -166°F (-110°C).
Despite the freezing cloud tops, temperatures rise dramatically the deeper you go into Jupiter's atmosphere and interior.
Jupiter's core is thought to reach temperatures of tens of thousands of degrees, hotter than the surface of the Sun.
A day on Jupiter isn't quite the same everywhere, since it's a gas giant that rotates slightly faster at the equator than near the poles.
Jupiter is so massive that its gravity strongly influences the orbits of many smaller bodies throughout the solar system.
If Jupiter had been roughly 80 times more massive, it could have become a star instead of a planet.
Jupiter is often called a "failed star" because its composition is similar to a star's, even though it never grew massive enough to ignite nuclear fusion.
Jupiter's gravity is more than twice that of any other planet in the solar system, about 2.5 times Earth's.
A 150-pound person on Earth would weigh nearly 380 pounds if they could somehow stand on Jupiter's cloud tops.
Jupiter's mass is roughly 318 times that of Earth.
Ancient Babylonian astronomers tracked Jupiter's movements across the sky more than 2,000 years ago.
In Hindu astronomy, Jupiter is known as Brihaspati or Guru, associated with wisdom and knowledge.
In Chinese tradition, Jupiter is called the "Wood Star" and was historically used to track a roughly 12-year cycle in the calendar.
Jupiter's storms can last for centuries, unlike storms on Earth that dissipate within days or weeks.
A smaller storm on Jupiter, nicknamed "Red Spot Jr.," formed in the early 2000s from the merger of several smaller storms.
Jupiter's cloud layer is relatively thin, only about 30 to 45 miles deep, sitting atop a much deeper atmosphere of hydrogen and helium gas.
Scientists believe Jupiter may have giant helium rain falling deep within its atmosphere, where droplets of helium separate out from the surrounding hydrogen.
Jupiter likely formed within the first few million years of the solar system's history, making it one of the oldest planets.
Some models suggest Jupiter may have migrated significantly closer to the Sun before settling into its current orbit, reshaping the young solar system in the process.
Jupiter's gravity is thought to have played a major role in shaping the asteroid belt between Mars and Jupiter, clearing out and scattering material over billions of years.
Jupiter's auroras, driven by its powerful magnetic field, are far more intense and permanent than the fleeting auroras seen on Earth.
Jupiter's auroras have been observed producing X-rays, a phenomenon not seen at any other planet in the solar system.
Io's volcanic activity constantly feeds material into Jupiter's magnetosphere, creating a donut-shaped ring of charged particles called the Io plasma torus.
Jupiter's moon system is sometimes described as a miniature solar system of its own, given how many moons orbit it.
New moons of Jupiter are still being discovered using powerful ground-based telescopes, decades after the first four were found.
Jupiter's outermost known moons are so far away and orbit so slowly that some take more than two Earth years to complete a single lap.
Jupiter has no fixed solid surface, so a spacecraft attempting to land would instead sink deeper and deeper into increasingly dense gas and liquid.
Jupiter's atmosphere lacks the layered cloud structure of Earth's weather systems, instead forming continuous, planet-circling bands of wind.
Jupiter's jet streams can blow at speeds exceeding 300 miles per hour, among the fastest sustained winds found on any planet.
Ganymede has its own thin oxygen atmosphere, though far too tenuous to support human breathing.
Ganymede is believed to have its own subsurface saltwater ocean sandwiched between layers of ice, adding it to the list of possible ocean worlds around Jupiter.
Callisto orbits far enough from Jupiter that it receives much less radiation than its inner Galilean siblings, making it an appealing potential site for future crewed exploration.
Io's surface is covered in colorful sulfur compounds, giving it a mottled yellow, orange, and red appearance often compared to a pizza.
Io has almost no impact craters, because its constant volcanic activity resurfaces the moon faster than craters can accumulate.
Jupiter's Great Red Spot rotates counterclockwise, completing one full spin roughly every six Earth days.
Astronomers have tracked the Great Red Spot since at least the 1830s, though some historical records may point to observations even earlier.
Jupiter's rings are far too faint to see with amateur telescopes and were unknown until spacecraft flew close enough to detect them.
Unlike Saturn's icy rings, Jupiter's ring system is thought to constantly lose material to space and be replenished by ongoing dust production.
Jupiter's gravitational influence is strong enough that it slightly tugs the Sun itself, causing the Sun to wobble around a point just outside its own surface.
Because of its brightness and steady position, ancient astronomers across many cultures independently tracked Jupiter as one of the five visible "wandering stars."
Jupiter's atmosphere contains small amounts of methane, water vapor, and ammonia in addition to its overwhelmingly hydrogen and helium composition.
Jupiter's fast rotation and internal heat combine to drive some of the most violent, long-lasting storm systems found anywhere in the solar system.
The Juno mission's name refers to the Roman goddess Juno, wife of Jupiter, who in mythology could see through the clouds the god used to hide himself.
Jupiter's four Galilean moons are large enough that all four could be seen as small disks, not just points of light, through a decent backyard telescope.
Because Jupiter is so massive, it barely moves in response to the Sun's gravity compared to smaller planets, making its orbit unusually stable over long timescales.
Jupiter's moons Io, Europa, and Ganymede are locked in a precise 4:2:1 orbital resonance, meaning their orbital periods form simple whole-number ratios.
This orbital resonance among Io, Europa, and Ganymede constantly stretches and squeezes their interiors, a major source of the internal heat driving Io's volcanoes.
Jupiter has been visited or studied by spacecraft from NASA, the European Space Agency, and, through flyby imaging, several international missions headed elsewhere in the solar system.
Jupiter's status as the solar system's largest planet has made it a common target for gravity-assist maneuvers, where spacecraft use its gravity to gain speed en route to more distant destinations.
New Horizons, the spacecraft that later flew past Pluto, used a gravity assist from Jupiter in 2007 to shorten its journey by about three years.

All Jupiter Facts

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