This page covers Jupiter’s storm systems as a whole — the polar cyclones, Oval BA, brown barges, white spots, lightning, and the wider cloud bands. For the full story of the most famous one, see our dedicated Great Red Spot page. To learn about Jupiter as a whole, see the main Jupiter pillar.
Jupiter has many kinds of storms: the famous Great Red Spot, the smaller “Red Spot Jr.” (officially called Oval BA), groups of giant polar cyclones in neat geometric patterns at both poles, long dark cyclones called brown barges, and bright anticyclonic storms called white spots. Some have lasted decades or even centuries.
With a small telescope on a clear night, you can see Jupiter’s cloud bands — the dark and light stripes that wrap around the planet. The bands are giant streams of cloud moving in different directions, and most of Jupiter’s storms live inside or between them. The Great Red Spot is small but visible with a 4–6 inch telescope when it is on the side facing Earth.
📋 Jupiter’s storms — Quick Facts
- Famous stormsGreat Red Spot, Oval BA (“Red Spot Jr.”), polar cyclones, brown barges, white spots
- Strongest storm windsAround the outer parts of the Great Red Spot, roughly 430–680 km/h (270–425 mph) depending on measurement
- Number of polar cyclones1 central + 8 around it at the north pole; 1 central + 5 around it at the south pole
- Polar cyclone sizesHundreds to thousands of kilometres across — some comparable in size to large countries
- Oval BA (“Red Spot Jr.”)About 8,000 km (5,000 mi) wide — enormous, but smaller than Earth
- Storm bandsRoughly 8 main alternating dark and light bands
- LightningYes — confirmed by every spacecraft from Voyager to Juno
- What powers the stormsInternal heat rising from deep inside Jupiter, plus the planet’s fast rotation
- Rotation speed (day length)About 9 hours 56 minutes — the fastest rotation of any planet
- Atmosphere compositionMostly hydrogen and helium (no breathable air)
Why is Jupiter so stormy?
Jupiter’s weather has two main engines:
- Heat from deep inside Jupiter. Unlike Earth, where the Sun is the main source of energy for our weather, Jupiter gives off more energy than it receives from the Sun. Heat rises from the planet’s deep interior and stirs up the atmosphere.
- Jupiter’s very fast spin. Jupiter rotates once every 9 hours 56 minutes — the fastest spin of any planet. That fast rotation stretches the storms out into long bands, and gives them their cyclone shapes.
These two engines together make Jupiter a storm factory. Storms form, merge, split, and sometimes fade, while the bigger ones can last for decades or centuries.
CYCLONE vs ANTICYCLONE — a cyclone spins around a low-pressure centre; an anticyclone spins around a high-pressure centre. On Earth, hurricanes are cyclones. On Jupiter, the Great Red Spot is an anticyclone, while the polar storms are cyclones. The exact spin direction depends on which hemisphere the storm is in — but the important idea is that cyclones and anticyclones are different kinds of spinning storms.
The polar cyclones — Jupiter’s strangest storms
In 2016, NASA’s Juno spacecraft became the first to fly over Jupiter’s poles. What it saw stunned scientists: groups of giant cyclones arranged in neat geometric patterns, spinning in formation, the same shapes for years.
- At the north pole, one central cyclone is surrounded by a ring of eight more.
- At the south pole, one central cyclone is surrounded by a ring of five more.
Each of these polar cyclones is enormous — hundreds to thousands of kilometres across, with some comparable in size to large countries. They have been spinning in those patterns since Juno first saw them, slowly drifting and reshuffling without breaking the formation.
Why do they stay in formation?
That question puzzled scientists for years. In 2022, an oceanographer named Lia Siegelman, working at the Scripps Institution of Oceanography in California, noticed that Jupiter’s polar cyclones look strikingly like ocean vortices on Earth — spinning currents in our seas. Her team found that the same process keeping ocean vortices spinning, called moist convection (hot, moist air rising and cooling), is what powers Jupiter’s polar cyclones too.
Recent research also suggests that Jupiter’s polar cyclones may slowly drift towards the pole over time, in a process called beta drift — similar to the way large storms can move on Earth. On our planet, hurricanes always break up before reaching the pole; on Jupiter, the storms don’t.
Imagine eight enormous hurricanes — each one the size of a large country — arranged in a perfect ring around a ninth central hurricane, all spinning the same way for years on end. That is Jupiter’s north pole. Now imagine if hurricanes on Earth could do the same thing. They can’t — our oceans and continents break them up. Jupiter has no continents to break its storms.
Oval BA — “Red Spot Jr.”
Jupiter’s second-biggest persistent storm is officially called Oval BA, but it has a more famous nickname: “Red Spot Jr.”
Oval BA formed in 2000 when three smaller white-coloured ovals (called BC, DE, and FA) merged into one. The merged storm was originally white. Then in 2006, scientists watching with the Hubble Space Telescope saw it slowly turn red — the same red colour as the Great Red Spot. Nobody is completely sure why.
Oval BA is about 8,000 km wide — enormous, but smaller than Earth (Earth is about 12,742 km wide). It sits south of the Great Red Spot, and the two storms have come close to one another several times. They’ve drifted past each other but never merged.
Scientists name Jupiter’s persistent storms with letter codes like Oval BA, NN-WS-4, or WS-a. These come from a system tracking where the storms sit in Jupiter’s atmosphere. The Great Red Spot has no letter code — it was named long before this system existed, around the 1660s–1700s.
Brown barges, white spots, and hot spots
Beyond the famous red ovals, Jupiter has hundreds of other storms with their own personalities. Here are a few of the strangest:
Brown barges
Long, dark, cigar-shaped features that can stretch tens of thousands of kilometres — several times wider than Earth. They were nicknamed “barges” after the long boats they resemble in images from the Voyager spacecraft in 1979. They are cyclones — spinning around a low-pressure centre — and they usually hide inside Jupiter’s dark belts.
White spots
Bright, oval-shaped anticyclones that look like white blobs on Jupiter’s clouds. Some last for years. Famous examples have nicknames like WS-a and NN-WS-4. White spots show up where storms push high clouds (which look bright white) above the rest of Jupiter’s clouds.
Hot spots
Dark patches near Jupiter’s equator that look unimpressive in visible light — but in infrared light, they glow as some of the brightest features on the planet. Hot spots are gaps in Jupiter’s clouds where you can see down to deeper, warmer levels of the atmosphere. In 1995, NASA’s Galileo spacecraft dropped a small probe into a Jupiter hot spot — the only time we have ever sampled Jupiter’s atmosphere directly.
Lightning on Jupiter
Yes — Jupiter has lightning. The Voyager 1 spacecraft saw the first lightning flashes on another planet when it flew past Jupiter in 1979. NASA’s Juno spacecraft later confirmed Jupiter’s lightning is more powerful than ours, and that it strikes much higher in the clouds than scientists expected — in places where the atmosphere is cold enough that liquid water shouldn’t exist by itself.
Scientists think Jupiter’s lightning may be triggered partly by tiny “mushballs” — hailstones made of ammonia and water that grow as they tumble through Jupiter’s storm clouds. These mushballs are a Juno discovery that completely changed how scientists understand Jupiter’s weather.
Jupiter’s storms only happen on the surface, like Earth’s weather.
Jupiter’s storms reach deep into the planet — some at least 3,000 km down. The Great Red Spot itself extends at least 300 km below the cloud tops, and possibly much further. Jupiter’s weather is not a thin shell on the surface — it goes a long, long way down.
Why are Jupiter’s cloud bands different colours?
Jupiter’s clouds form in alternating dark and light bands. The lighter bands are called zones, and the darker bands are called belts. Each band is a giant river of moving cloud, and neighbouring bands move in opposite directions.
- Zones (light bands) — cool air rising from below, forming bright clouds of ammonia ice at the top
- Belts (dark bands) — warm air sinking, revealing deeper darker clouds underneath
The boundaries between zones and belts are where storms tend to form. The cold air rising and warm air sinking meet at the edges, creating turbulence and giving Jupiter its endless storm patterns. The Great Red Spot sits right at the boundary between the South Tropical Zone and the South Equatorial Belt.
Much of what we know about Jupiter’s polar storms comes from NASA’s Juno spacecraft, which has flown closer to Jupiter than any orbiter before. Juno’s polar passes revealed the geometric polar cyclones for the first time, its microwave radiometer measured how deep Jupiter’s weather goes (about 3,000 km), and its instruments confirmed Jupiter’s lightning is much higher in the clouds than scientists thought. Read more about Juno →
Jupiter’s polar cyclones are a great way to compare Earth and Jupiter weather. Ask students: why don’t Earth’s hurricanes form geometric patterns at our poles? (Hint: Earth has continents and warm oceans, which break storms up before they reach the poles. Jupiter has no surface to break its storms, and its strong rotation keeps them spinning in formation.) This connects atmospheric science with planetary geography in a kid-friendly way.
Frequently asked questions about Jupiter’s storms
How many storms does Jupiter have?
Jupiter has hundreds of storms at any given time — maybe thousands if you count all the small ones. The biggest and most famous is the Great Red Spot. Others include Oval BA (“Red Spot Jr.”), the polar cyclones, brown barges, white spots, and many more.
What is the biggest storm on Jupiter?
The Great Red Spot — a giant anticyclone roughly Earth-sized today. Its exact width changes over time as the storm shrinks, stretches, and wobbles. It has been observed for at least 195 years (and possibly more than 350). The second-biggest persistent storm is Oval BA, also known as “Red Spot Jr.”
Are Jupiter’s polar cyclones real?
Yes. NASA’s Juno spacecraft photographed them clearly starting in 2016. At Jupiter’s north pole there is one central cyclone surrounded by a ring of eight more. At the south pole there is one central cyclone surrounded by five more.
Does Jupiter have lightning?
Yes. NASA’s Voyager 1 spacecraft spotted the first lightning flashes on Jupiter in 1979, making it the first lightning ever seen on another planet. NASA’s Juno later showed that Jupiter’s lightning is more powerful than Earth’s and strikes higher in the clouds than scientists expected.
How deep do Jupiter’s storms go?
Far deeper than scientists used to think. Juno’s measurements suggest the cloud bands and many storms reach about 3,000 km below the visible surface. The Great Red Spot itself extends at least 300 km down and possibly up to 500 km.
What is Oval BA?
Oval BA is Jupiter’s second-biggest persistent storm, nicknamed “Red Spot Jr.” It formed in 2000 when three smaller white storms merged together, then turned red in 2006. It is about 8,000 km wide — enormous, but smaller than Earth (which is about 12,742 km wide).
What is a brown barge?
A brown barge is a long, dark, cigar-shaped cyclone hidden inside Jupiter’s dark belts. They can stretch tens of thousands of kilometres long. The nickname came from images taken by NASA’s Voyager spacecraft in 1979 — the storms looked like long boats.
What are mushballs?
Mushballs are a recent Juno discovery — tiny hailstones made of ammonia and water that grow as they tumble through Jupiter’s storm clouds. They might explain why Jupiter’s lightning strikes so high in the atmosphere.
Could storms like Jupiter’s happen on Earth?
Not really. Earth is much smaller, doesn’t rotate as fast, has continents and warm oceans that break up storms, and gets most of its weather energy from the Sun rather than from heat rising from inside the planet. Jupiter’s storms are uniquely Jovian.
Are Jupiter’s storms dangerous to Earth?
No. Jupiter is hundreds of millions of kilometres away, and its storms stay inside Jupiter’s atmosphere. They cannot affect Earth in any way.
Why do Jupiter’s storms last so long?
Jupiter has no solid ground, oceans, or continents to break storms apart. Its fast spin and the heat rising from inside the planet can keep storms moving for years, decades, or even centuries. The Great Red Spot has been watched for at least 195 years.
Is the Great Red Spot the only storm on Jupiter?
No. The Great Red Spot is the most famous storm, but Jupiter has many others, including Oval BA (“Red Spot Jr.”), the polar cyclones, brown barges, white spots, and many smaller storms in its cloud bands.
What powers Jupiter’s storms?
Two things together: heat rising from deep inside Jupiter (the planet gives off more energy than it receives from the Sun), and Jupiter’s extremely fast rotation (one day = about 9 hours 56 minutes). Together, these create the storm patterns and bands we see.
Quick recap
- Jupiter is the stormiest planet in the solar system
- Its storms are powered by heat rising from inside Jupiter and the planet’s very fast spin
- Famous storms: Great Red Spot, Oval BA (“Red Spot Jr.”), polar cyclones, brown barges, white spots
- The polar cyclones form geometric patterns — 8 around 1 at the north pole, 5 around 1 at the south pole
- Jupiter has lightning — more powerful than Earth’s, and higher in the clouds
- Some storms reach 3,000 km deep into Jupiter
- NASA’s Juno mission revealed Jupiter’s polar storms in detail for the first time
Want to learn more about Jupiter’s most famous storm? Visit the Great Red Spot page, or learn how Juno is studying these storms from up close.