Level 1 — Absolute Beginner
Saturn is a big planet in space. It is the second biggest planet in our solar system. Saturn is a gas giant. This means Saturn is made mostly of gas, not hard rock. Saturn also has beautiful rings around it.
A telescope is a tool that helps us see things far away, like planets and stars. NASA has a telescope in space called Hubble. Hubble takes pictures of Saturn.
New Hubble pictures show something strange at the south pole of Saturn, the bottom part of the planet. There is a wave shape with ten sides. Scientists call this shape a decagon.
Saturn's north pole, the top part, has a different shape with six sides, called a hexagon. This hexagon has been there for a very long time. Now scientists want to watch the new ten sided shape and learn more about it.
- planet
- A very large round object in space that moves around a star.
- telescope
- A tool that helps people see things that are very far away.
- shape
- The form or outline of an object, like a circle or a square.
- wave
- A moving line or pattern, like ripples of water.
- pole
- The very top or very bottom point of a planet.
- gas giant
- A huge planet made mostly of gas instead of rock.
- scientist
- A person who studies the world and space to learn new things.
- atmosphere
- The layer of air and gas around a planet.
Level 2 — Elementary
Saturn is the second largest planet in our solar system. It is called a gas giant because it is made mostly of gas rather than solid rock. Saturn is also known for the beautiful rings that circle around it.
NASA's Hubble Space Telescope has been watching Saturn for many years, taking detailed pictures of the planet from space. Scientists use these pictures to study the weather and wind patterns in Saturn's atmosphere.
Recently, Hubble found something new and surprising near Saturn's south pole. A giant wave with ten sides and ten corners appeared in the atmosphere there. Scientists call this shape a decagon.
This is unusual because Saturn's north pole has a famous six sided shape called a hexagon, first seen by the Voyager 1 spacecraft in the 1980s and studied closely by the Cassini spacecraft later. Until now, scientists thought the south pole only had a plain, round spinning mass of air. Hubble first noticed faint hints of the ten sided shape in 2023, and by August and September 2025 the pattern had become clear and fully formed.
- solar system
- The sun and all the planets, moons, and other objects that move around it.
- gas giant
- A large planet made mostly of gas instead of solid rock.
- spacecraft
- A vehicle built to travel and explore in space.
- atmosphere
- The layers of gas that surround a planet.
- jet stream
- A fast moving band of wind high in a planet's atmosphere.
- hexagon
- A shape with six straight sides and six corners.
- decagon
- A shape with ten straight sides and ten corners.
- vortex
- A spinning mass of air, water, or gas.
Level 3 — Intermediate
Saturn, the second largest planet in the solar system, has long fascinated astronomers with its extensive ring system and its status as a gas giant, a planet composed primarily of gas rather than solid rock. For decades, most attention to Saturn's polar regions has focused on the north, where a persistent six sided jet stream pattern known as the hexagon has intrigued scientists since it was first observed by the Voyager 1 spacecraft in the 1980s and later examined in detail by the Cassini spacecraft.
Saturn's south pole, by contrast, was thought to host a far less remarkable feature: a plain, round polar vortex, a rotating mass of air with no distinctive many sided structure. That assumption has now been overturned by new observations from NASA's Hubble Space Telescope.
Hubble first detected faint traces of a ten cornered polygon near Saturn's south pole in 2023, but the feature remained indistinct. New images captured in August and September of 2025 reveal that the pattern has sharpened considerably, forming a fully defined decagon, a shape with ten sides and ten corners, embedded within one of Saturn's powerful jet streams and extending through multiple layers of the planet's atmosphere.
Researchers describe this as the first time such a large, regular, many sided jet stream pattern has been observed in Saturn's southern hemisphere, and they suggest they may be witnessing an atmospheric phenomenon developing in real time, given how much more distinct the shape has become since 2023. Scientists plan to continue monitoring the feature with Hubble to determine how it formed and whether it will prove as stable and long lasting as its northern counterpart, which has persisted for decades.
- polar vortex
- A large, rotating mass of cold air centered near a planet's pole.
- polygon
- A shape with multiple straight sides and corners.
- jet stream
- A fast flowing, narrow band of wind found at high altitudes in a planet's atmosphere.
- atmospheric phenomenon
- A notable event or pattern occurring within a planet's layers of gas.
- hemisphere
- Half of a planet, typically divided into northern and southern regions.
- spacecraft
- An engineered vehicle designed for travel and observation beyond Earth's atmosphere.
- gas giant
- A large planet composed mainly of gas, with no well defined solid surface.
- indistinct
- Not clearly defined or easy to make out.
Level 4 — Advanced
For nearly half a century, Saturn's polar meteorology has been defined by an asymmetry that seemed almost too tidy to be coincidental: a striking six sided jet stream encircling the north pole, first glimpsed by Voyager 1 in the 1980s and later mapped in exquisite detail by Cassini, set against a southern pole presumed to harbor nothing more distinctive than an ordinary, round polar vortex. New observations from NASA's Hubble Space Telescope have now dismantled that assumption.
Hubble first registered faint, ambiguous hints of a ten cornered polygon near Saturn's south pole in 2023, a signal too indistinct at the time to be described with confidence. Images gathered in August and September of 2025 remove that ambiguity: the feature has sharpened into a fully articulated decagon, threaded through one of the planet's powerful jet streams and extending across multiple layers of the atmosphere, a structural signature that scientists say has never before been documented in Saturn's southern hemisphere.
What makes the discovery notable is not merely its geometry but its apparent immaturity. Because the decagon has become markedly more defined in the roughly two years since its first, faint detection, researchers suspect they may be observing an atmospheric phenomenon caught in the act of forming, rather than a static feature simply overlooked until now. That distinction carries real scientific weight for a gas giant whose banded, gaseous composition makes such large scale organized wave patterns inherently difficult to explain.
The comparison to the northern hexagon is unavoidable, and deliberately so: that feature has endured for decades, making it one of the most durable organized structures known in any planetary atmosphere. Whether the southern decagon will prove similarly persistent, or whether it represents a more transient episode in Saturn's turbulent weather system, remains an open question. NASA scientists intend to keep monitoring the feature with Hubble, treating its evolution as a live test of how, and why, such symmetrical wave patterns emerge in a gas giant's atmosphere at all.
- meteorology
- The scientific study of atmospheric conditions and weather patterns.
- asymmetry
- A lack of similarity or balance between two sides or aspects of something.
- polar vortex
- A large scale rotating weather system centered on a planet's pole.
- articulated
- Clearly formed and defined in structure.
- atmospheric phenomenon
- A significant and identifiable pattern or event occurring within a planet's gaseous layers.
- transient
- Lasting only for a short time; not permanent.
- gaseous composition
- The makeup of a body formed mainly from gas rather than solid material.
- organized structure
- A pattern that displays consistent, non random form over time.
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