Saturn
28 questions tagged Saturn — spanning every one of the seven Ws.
When did the Cassini mission end?
NASA's Cassini spacecraft ended its mission on 15 September 2017 by diving into Saturn's atmosphere after 13 years orbiting the planet.
Which moon has a thick atmosphere?
Titan, Saturn's largest moon, is the only moon in the solar system with a thick atmosphere, denser than Earth's.
Which moon sprays water into space?
Saturn's moon Enceladus shoots jets of water vapour and ice grains into space from cracks near its south pole.
Which planet has the lowest density?
Saturn is the least dense planet in the solar system, with an average density of about 0.69 g/cm³ — less than water.
Why is Saturn less dense than water?
Saturn is made mostly of hydrogen and helium, which are very light elements. Its average density is only about 0.69 g/cm³, lower than water’s 1.0 g/cm³.
Why do Saturn’s rings stay as separate rings instead of becoming one moon?
The rings lie inside Saturn’s Roche limit, where strong tidal forces prevent the particles from clumping into a single body. They are also constantly shaped by moonlets and shepherd moons.
When was the first spacecraft to fly by Saturn?
Pioneer 11 flew past Saturn on 1 September 1979. It was the first spacecraft to observe Saturn up close.
When was the first spacecraft to visit Saturn?
Pioneer 11 became the first spacecraft to fly by Saturn in 1979.
When was the first spacecraft to orbit Saturn?
Cassini entered Saturn orbit in 2004 and became the first spacecraft to do so.
Where are Saturn’s rings located?
Saturn’s rings are in orbit around Saturn, lying mostly within about 280,000 km of the planet’s center. They are made mainly of water ice with smaller amounts of rock and dust.
Whose observation first revealed Saturn’s rings as separate from the planet?
Galileo Galilei first observed Saturn’s unusual shape in 1610, but Christiaan Huygens explained in 1655 that Saturn is surrounded by a ring. Huygens also discovered Titan.
How do scientists infer that Saturn’s rings are surprisingly young and thin?
They study the rings’ mass, brightness, and how quickly they collect dark dust and lose material. Data from Cassini suggests the rings are likely only hundreds of millions of years old, not as old as Saturn itself.
How do Saturn’s rings stay divided into separate bands and gaps?
Moons and orbital resonances sculpt the rings by tugs of gravity. Small shepherd moons and resonant interactions keep many gaps sharp and well defined.
Why is Saturn so much less dense than water?
Saturn is made mostly of hydrogen and helium, so its average density is only about 0.69 g/cm³, lower than water’s 1.0 g/cm³.
Where is Saturn’s hexagon found?
Saturn’s famous hexagon is at the planet’s north pole. It is a jet stream pattern with a distinct six-sided shape.
Where is the Cassini Division found?
The Cassini Division is a gap in Saturn’s rings. It separates the A ring from the B ring.
Which planet has the most rings?
Saturn has by far the most extensive and visible ring system of any planet. Its main rings stretch hundreds of thousands of kilometers across.
Which planet has the brightest rings seen from Earth?
Saturn has the brightest rings visible from Earth. Their high reflectivity comes largely from abundant water ice.
Whose telescope observations first revealed that Saturn is surrounded by rings?
Those observations were made by Galileo Galilei in 1610, though he did not fully understand what he was seeing at first. Christiaan Huygens later correctly explained the rings in 1655.
How do Saturn's rings stay so thin and flat?
The rings are made of countless icy particles that orbit at nearly the same plane, with gravity from Saturn and its moons confining them into a thin disk.
Why do the rings of Saturn look so thin from Earth?
Saturn’s rings are extremely wide but very thin, only tens of meters thick in many places, so they appear as a narrow line from far away.
Why is Saturn so low-density?
Saturn is made mostly of hydrogen and helium, so its average density is less than water. If there were a bathtub large enough, Saturn would float in it.
Why do Saturn's rings look so flat and thin?
The rings are made of countless icy particles orbiting in the same plane, and collisions keep them very thin. From Earth, that makes them look like a narrow line when edge-on.
When did the first photos of Saturn’s rings from close range arrive on Earth?
The first close-range images of Saturn’s rings came on 1 September 1979 from Pioneer 11.
Where is Saturn’s hexagon storm located?
Saturn’s hexagon is at the planet’s north pole. It is a giant six-sided jet stream surrounding a polar vortex.
Where is Saturn’s main ring system located?
Saturn’s main ring system circles the planet’s equator. It is the most spectacular ring system in the Solar System.
Which planet has the greatest number of known ring segments?
Saturn has the most extensive and complex ring system, with thousands of ringlets and gaps. Its main rings are labeled A, B, C, D, E, F and G.
Whose telescope first revealed the rings of Saturn as a distinct feature?
Galileo Galilei first saw Saturn’s strange shape in 1610, although he did not understand the rings. Christiaan Huygens later correctly identified them as a ring system in 1655.