Approaching the mysterious Saturn "necklace", what is under the beautiful appearance? Where did it come from?

Of all the planets in the solar system, it seems that no planet has the unique charm that attracts us like Saturn. The fascinating reason may be that its huge halo makes it stand out in our solar system. Although Jupiter, Uranus and Neptune all have their own rings, none of them is more spectacular than Saturn's rings.

Illustration: The photos returned by Cassini-Huygens spacecraft depict Saturn's unique planetary rings.

Saturn's rings are also a great mystery in space. However, as our spacecraft get closer to the halo than ever before, we will have a more complete understanding of their composition and how they exist.

Saturn has six main rings, each of which consists of thousands of small rings. These rings are huge-the largest ring diameter spans170,000 miles (273,588 kilometers). But their thickness is very thin-only about 650 feet (200 meters) thick. From the earth's point of view, they are not solids, but are made up of floating water, ice, rocks and dust, ranging in size from spots to huge fragments similar to the size of houses, all of which orbit Saturn in a ring. With the orbital motion of debris particles, they constantly collide with each other and crush larger debris.

Illustration: The panoramic view of Saturn's rings taken by Cassini Huygens on September 15, 2006 (the brightness is enhanced in this view).

Saturn's rings are not perfectly round, and some places will be bent by the gravity of nearby satellites. The ring also contains spokes, which are generated by electrostatic attraction and tension of extremely fine dust particles floating on the ring.

Illustration: Souster Mans (about 1637). Painted a portrait of Galileo.

These rings are named by letters-A, B, C, D, E and F. They are not arranged alphabetically, but in the order of discovery (the actual order from Saturn is-D, C, B, A, F, G and E).

A and B are the brightest two rings, and B is the widest and thickest of the six rings. C is sometimes called a yarn loop because it is very transparent, while D is almost invisible. The F-ring is very narrow and is squeezed and bound by Pandora and Prometheus, which are located inside and outside the ring. This is why these two satellites are called "shepherd satellites" because they control the movement of particles in the ring.

Illustration: The dark Cassini seam separates the wide inner ring B from the outer ring A. This image was taken by the Hubble Space Telescope's advanced survey camera on March 22, 2004, and the less obvious C ring is located inside the B ring.

Further away from other rings is the G ring, and finally the E ring, which is composed of very fine (almost microscopic) particles. E-ring has always puzzled scientists, because unlike other rings, E-ring is considered to be composed of particles scattered by nearby satellites, and E-ring is considered to be composed of ice particles ejected by volcanic geysers near Enceladus' South Pole. The gaps between rings are named after astronomers who study Saturn.

Illustration: Saturn's rings seen from the dark side by Cassini spacecraft (May 9, 2007).

But how are these rings formed and how old may they be? Let's analyze it below.

The origin of Saturn's rings

Ever since Galileo gazed at Saturn through an early telescope in 16 10, scientists have been thinking about what Saturn's rings look like. Galileo speculated from his observation that Saturn is not a star, but three stars: a large and medium-sized star with two ear-shaped appendages, which he thought might be a large satellite. Galileo has been observing Saturn for more than a year. Then he rested for a while and saw nothing unusual until 16 12 re-observed. Galileo saw only one star this time, not the three he saw last time. He correctly predicted that other "stars" would come back, but he didn't understand why they disappeared.

Illustration: The enhanced image of Voyager 2 shows details that galileo telescope can't see.

1655, when Dutch scientist christiaan huygens observed Saturn through a more complicated telescope, he answered the question that puzzled Galileo. He thinks that the redundant stars are actually rings. They are so thin that they seem to disappear from the edge. Now, scientists have named the discoveries of Galileo and Huygens as torus crossing. When Saturn orbits the sun, its rings face the earth about once every 14 years. Therefore, when we observe the planets through telescopes during this time, these rings are invisible.

Illustration: In the image of Saturn's ring depicted by the artist in 2007, cold particles gather in the solid part of the ring. Slender clusters are constantly formed and dispersed, and the largest particle diameter is only a few meters.

Huygens made a mistake in evaluating Saturn. He thinks Saturn's rings are solid. Five years later, the French astronomer Jean Chamberlain speculated more accurately that these rings were actually small particles orbiting Saturn. Scottish physicist james clerk maxwell confirmed this theory. In 1857, he discovered that rings must be composed of small particles. If they are not made of small particles, they will be pulled inward by Saturn's gravity until they fall into Saturn.

Illustration: The image taken by Cassini's small-angle camera is a mosaic of natural colors, and the rings of D, C, B, A and F are not smooth from left to right, dated May 9, 2007.

In the 20th century and 2 1 century, astronomers benefited from technology, which can help them discover the secrets of Saturn's rings. In the late 1970s and early 1980s, the spaceships Pioneer and Voyager sent back close-up photos of rings and their particles. In recent years, the Cassini mission (a joint effort of NASA, ESA and the Italian Space Agency) has been able to run in an orbit closer to Saturn's ring and collected a lot of new information about their structures.

Illustration: Illustration of Cassini spacecraft in Saturn's orbit.

With more and more knowledge about the composition of Saturn's rings, scientists have been questioning the origin of rings. They believe that when a comet or asteroid collides with a satellite of one or more planets and breaks it into many pieces, it will produce a halo. Debris from the collision scattered around Saturn, forming the present ring shape.

Illustration: Saturn's rings are on the light receiving side, and the main details are marked with.

The age of the ring is also uncertain. At first, people thought they were as old as the solar system. Then scientists speculated that if dust had been accumulated for 4 billion years, the ice in the ring would be much dirtier. Therefore, they pushed the estimated life of the ring to tens of millions of years ago. However, when the Cassini spacecraft sent back the clearest image of Saturn's rings to date, scientists said that the initial guess might be correct. They believe that ring particles are likely to be recycled after 4 billion years, and they will continue to exist for a long time to come.

reference data

1.WJ encyclopedia

2. Astronomical terminology

3. Stephanie Watson-Cold Dust-Science

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