The planet Saturn has become widely known to everyone due to its beautiful rings that revolve around the planet. are divided into three main groups: A, B, C. It is easy to distinguish these groups even from Earth, but if you examine the rings from a relatively close distance, it turns out that there are not 3 groups of them, but much more. There are small gaps between the rings where there are no particles.
The approximate width of the rings is 400 thousand kilometers, and the thickness of the ring is only a few tens of meters. The rings of Saturn consist of various objects: from dust to pieces of ice several meters in diameter. Surprisingly, these particles move at almost the same speed of 10 km/s and they do not seem to move relative to each other.
Saturn's rings were first discovered by Galileo Galilei in 1610. When Galileo saw the rings of Saturn through a telescope, he did not understand what they were and thought that Saturn was made up of different parts. He could not say exactly what he saw at Saturn - all that could be seen. At that time, telescopes were not so powerful. He saw some foggy objects around the planet. Almost 50 years later, scientists finally established that Saturn has rings, and a little later a gap between them was found using the Cassini spacecraft.
Rings cannot always be seen through a telescope from Earth. orbits the Sun for about 30 years, and every 15 years or so the planet tilts toward Earth so that the rings appear as a barely visible line along Saturn's equator. At this time, the rings are considered invisible from Earth and Saturn is almost no different from its neighbors. The last such period was around 2009.
The particle sizes in the rings are negligible. They vary from a few centimeters to a couple of meters. In rare cases, the particle size exceeds 2 meters. But group B particles are significantly larger than all other particles. Here you can find relatively huge particles ranging in size from hundreds of meters to, in rare cases, several kilometers.
The structure of Saturn's rings
Rings are divided into 3 main groups: A, B, C; but in total there are 2 times more groups of rings. Rings A, B and C are the most noticeable and brightest relative to the other groups. All these groups break up almost imperceptible dark areas, which were later called “cracks.” Between groups A and B there is a “Cassini gap”, named after the scientist who discovered it. Next, between groups B and C there is a “French separator”, and between the rings of groups A and B there is an “Encke minima”.
The image shows Saturn's rings at a time when they are difficult to see from Earth. One of Saturn's moons can be seen on the left in the photo.
In this photo from the Cassini spacecraft, you can see the E, F, G rings. These groups of rings are the furthest from the surface of the planet, and they are invisible to Earth's telescopes.
How Saturn's rings formed is still unclear. Astronomers suggest that Saturn's rings consist of fragments of its satellites, which collided in the planet's orbit and then their fragments were captured by the planet's gravitational force. Perhaps there were quite a few of these satellites, since there are a lot of fragments and debris in the rings of the planet. Others believe that the formation of the rings occurred at the same time as the formation of the planet and they are in no way related to cosmic collisions of satellites.
So far there is no evidence for one theory or another. Therefore, it is impossible to establish the true nature of the rings. But no matter how they were formed, they made the planet Saturn the most beautiful planet, at least in the solar system. Thanks to these rings, the planet can be distinguished from all other planets.
I finished school quite a long time ago, but my astronomy lessons are well preserved in my memory. I have always been interested in hearing stories about planets of the solar system. Outer space beckons with its beauty and the unknown. So, for example, Saturn counts the most beautiful planet. I’ll tell you why this particular planet received such a title.
Rings of Saturn
There are several planets surrounded by rings. The most famous among them is Saturn. It's easy to recognize her. Saturn is surrounded by a whole system of ring formations.Compound they have long been known:
- crushed ice particles;
- dust;
- space debris.
Rings of Saturn clearly visible through a telescope from Earth. This is possible due to the fact that ice particles have the ability to reflect sunlight.
Saturn's rings are divided into seven classes, designated by the first English letters of the alphabet: A, B, C, D, E, F, G. The first three rings A, B and C are best seen from the Earth. If we consider these rings in more detail, then each of them consists of thousands of small rings. The main rings do not all fit tightly together. There are quite large gaps between them.
How were Saturn's rings formed?
Eat two assumptions How the rings of the planet Saturn could have arisen. According to the first assumption, the formation of rings was caused by crash of a satellite, asteroid or comet, located close to Saturn. Such destruction could have occurred due to exposure tidal force of the planet. The cosmic body could be pulled so close to her that it simply broke into small pieces.
According to the second hypothesis, rings of saturn represent remnants of a huge circumplanetary cloud. It can be assumed that large parts of it formed satellites of the planet, and the little ones still have fragmented view. This is due to the fact that Saturn does not have a constant attraction, and parts of the cloud could not fully connect, and therefore remain in fragmented form. The photographs of this planet are impressive. It’s not for nothing that most scientists call Saturn the most beautiful planet.
Here's what they look like:
Saturn's rings are unusually thin: although they are about 250,000 kilometers in diameter, they are no more than 1.5 kilometers thick. Saturn is surrounded by three rings (A, B and C), which, like the planet’s equator, are inclined to the plane of its orbit at an angle of 26°45’. There are also weaker rings - D, E, F. Upon closer examination, there are even more rings.
The inner parts of the rings rotate faster than the outer ones.
The outer ring is separated from the middle by a dark gap - the Cassini gap. The middle ring is the brightest. It is also separated from the inner ring by a dark gap. The inner dark and translucent ring is called crepe. Its edge is blurred, the ring gradually disappears.
These rings are made up of dust, pieces of ice and rocks. Their sizes range from a centimeter to several meters.
Why are the rings flat? Their shape is the result of the action of two forces: gravitational (attraction) and centrifugal. Gravitational attraction tends to squeeze them from all sides. The rotation of the rings prevents compression across the axis of rotation, but cannot prevent it from flattening along the axis.
Where did they come from? There are two hypotheses about this.
According to the first theory, the rings appeared as a result of the crash of a careless satellite, comet or asteroid that approached Saturn. The destruction of the “alien” body could have occurred due to the influence of the tidal forces of the giant Saturn, which literally tore it “to shreds” with its powerful gravity. Calculations showed that if the satellite had formed at the same distance as the rings, it would have been torn into small fragments by tidal force.
According to another hypothesis, Saturn's rings are the remains of a huge circumplanetary cloud. Satellites have formed from the outer regions of this cloud, while the inner ones are still in a fragmented state, that is, in the form of rings. They were unable to form satellites due to the inconsistent gravity of Saturn, they rotated and collided too randomly, and because of this they were constantly crushed, so that they reached such a loose state that they crumble at the slightest shock.
Did you know...
The rings of Saturn were first discovered by Galileo Galilei in 1610. He saw a very blurry image through his telescope: Saturn seemed to have two ears, or appendages: Saturn's rings looked like two hazy spots on the sides of the planet. Galileo thought that these could be large satellites: “I observed the most distant of the planets as a triple.” As Galileo put it figuratively, the appendages resembled “two servants who support old Saturn (the god of time among the ancient Romans) on his weary journey across the sky.”
In addition to its rings, Saturn has 62 satellites. The most famous and largest is Titan. It is the only satellite in the solar system on which an atmosphere has been discovered.
There are 3 main rings, named A, B and C. They are visible without much trouble from Earth. There are also weaker rings - D, E, F. Upon closer examination, there are a great many rings. There are gaps between the rings where there are no particles. The one of the gaps that can be seen with an average telescope from Earth (between rings A and B) is called the Cassini gap. On clear nights, you can even see less visible cracks. The inner parts of the rings rotate faster than the outer ones.
RINGS OF SATURN |
The width of the rings is 400 thousand km, but their thickness is only a few tens of meters. Stars can be seen through the rings, although their light is noticeably weakened. All rings consist of individual pieces of ice of different sizes: from specks of dust to several meters in diameter. These particles move at almost identical speeds (about 10 km/s, their speeds are so well balanced that neighboring particles appear motionless in relation to each other), sometimes colliding with each other. Under the influence of satellites, the ring bends slightly, ceasing to be flat: shadows from the Sun are visible. Nevertheless, the particles move slowly in different directions - at a speed of 1-2 mm/s.
The appearance of the rings varies from year to year. This is due to the inclination of the plane of the rings to the plane of the planet’s orbit. The plane of the rings is inclined to the orbital plane by 26°. Therefore, during the year we see them as wide as possible, after which their apparent width decreases, and, after about 15 years, they turn into a faintly distinguishable feature. In 1610, Galileo Galilei first saw Saturn's rings through a telescope, but did not understand what they were, so he wrote down that Saturn was made up of parts.
In July 1610, Galileo Galilei published an encrypted message with the following content: “The most distant of the planets was observed by a triple one.” At that time, Saturn was considered the “most distant of the planets,” and its rings appeared in Galileo’s telescope as two hazy spots along the edges of the planet.
Half a century later, Christiaan Huygens reported the presence of a ring on Saturn, and in 1675 Cassini discovered a gap between the rings.
The rings of Saturn have constantly excited the imagination of researchers with their unique shape. Kant was the first to predict the existence of the fine structure of Saturn's rings. Using his model of a protoplanetary cloud, he imagined a ring in the form of a flat disk of colliding particles rotating differentially around the planet according to Kepler's law. It is differential rotation, according to Kant, that causes the disc to separate into a series of thin rings. Later, Simon Laplace proved the instability of a solid wide ring. In the middle of the last century, astronomers discovered ten rings around Saturn. An outstanding contribution to the study of the stability of Saturn's rings was made by James Maxwell, who received the Adams Prize for his work in which he showed that such narrow rings are also unstable and will fall into the planet. And although Maxwell’s conclusion about the fall of a hypothetical solid ring of ice onto the planet was incorrect (such a ring should fall into pieces much earlier), the consequence from it - the meteoric structure of the knees of Saturn - turned out to be correct. Thus, by the end of the 19th century, the hypothesis of the meteoric structure of Saturn’s rings, first expressed by Jean Cassini, received theoretical and, in 1893, observational confirmation. During the 20th century, new data on planetary rings was gradually accumulated: estimates of the size and concentration of particles in the rings of Saturn were obtained, spectral analysis established that the rings are icy, and the mysterious phenomenon of azimuthal variability in the brightness of Saturn's rings was discovered.
Over the course of 29.5 years from the Earth, the rings of Saturn are visible twice at their maximum opening, and twice there are periods when the Sun and Earth are in the plane of the rings, and then the rings are either illuminated by the Sun “edge-on”, or it is visible “edge-on” to an earthly observer. . During this period, the rings are almost completely invisible, which indicates their very small thickness. Various researchers, based on visual and photometric observations and their theoretical processing, come to the conclusion that the average thickness of the rings ranges from 10 cm to 10 km. Of course, it is impossible to see a ring of such thickness from the Earth edge-on.
In accordance with Kepler's laws, particles at different radii of the ring move at different speeds: the closer to the planet, the faster. In the densest ring there is a region where particles circulate with a period of 10.5 hours, i.e. at the same angular speed as Saturn rotates. This means that relative to the surface of the planet they remain motionless.
What did Voyagers learn?
Already the first images of the rings transmitted by Voyager 1 showed slight color variations in the rings, a gap in the C ring, the presence of matter in the Cassini fission, and changes in the distribution and brightness of matter in the C and B rings. The most interesting details in the first images were "spokes" are radial dark features that intersect parts of the bright B ring. Sometimes "spokes" were observed for several hours, although the inner edge of the ring at the base of the "spoke" rotates around the planet at a faster speed than the outer edge at the top of the "spoke", and these formations would have to collapse.
Later, photographs were taken of the “spokes” as sunlight scattered forward. In these pictures the spoke areas are light, not dark as in the first pictures taken with the light scattered back. This suggested that the "spoke" areas contained very fine dust particles. The region where the "spokes" are observed overlaps the ring zone that orbits Saturn at the same speed as its magnetic field. This, according to some scientists, may explain the stability of the spokes, despite the different speeds of particle movement. Scientists hypothesized that as a result of the interaction between these mogul particles and electrostatic forces, the particles could concentrate in certain areas or rise above the plane of the rings. If the ring is charged, the particles in it should repel each other, but gravitational forces keep them in the ring. For large particles, the gravitational force is greater than the repulsive force, and they remain in the ring; for small particles, the repulsive force is greater, and they rise above the plane of the ring. It has been hypothesized that the planet's magnetic field affects the charged small particles above the B ring, "arranging them like iron filings" or causing them to stick together. Another hypothesis explains the existence of the spokes by wave phenomena around the ring, which influence small particles in the path of the wave. The mechanism responsible for the charge of the ring is unclear. Hypotheses have been proposed that this occurs under the influence of Saturn's atmosphere or high-energy ultraviolet radiation from the Sun.
The images showed that each of the previously observed six rings of Saturn (D, C, B, A, F, E - in order of increasing distance from the planet) consists of a large number of narrow rings. It was believed that after complete processing of the images they could count 500 - 1000 narrow rings. Several narrow rings were also found in the Cassini division, which was previously thought to be a relatively matter-free space.
Forward scattering imaging showed that the particles in the rings range in size from a few microns to several meters. Based on the nature of the passage of Voyager 1 radio signals through the C ring, it was concluded that the size of particles in this ring ranges from 10 cm to 10 m, and for each particle 10 m in size there are approximately 1000 particles 1 m in size and approximately a million small ones particles. The small particles appear to be composed of ice, while the larger particles appear to be snow with ice inclusions. It was later reported that, according to radio sounding data, the average particle size in the C ring is 1 m, and some reach 10 m. It was noted that previously a smaller average particle size was assumed. It was also reported that, as shown by radio sounding and infrared measurements, the particles were pieces of ice or silicates with an ice coating. Still, the bulk of the rings is contained in meter-sized particles.
From time to time you can see an effective spectacle - a collision of two large particles. Here two blocks the size of a garden house begin to slowly come into contact with each other, shifting entire drifts of loose snow from the surface. They were unlucky: they could not withstand the mutual pressure upon impact and slowly fell apart. A typical “disaster” for rings at a speed of a millimeter per second! The two remnants of the original bodies continue to move, and the snowdrifts, lumps and snow dust thrown from them slowly scatter in different directions, sparkling in the rays of the distant Sun. After a few days, the “damaged” particles will grow again, trapping and absorbing huge amounts of smaller snowballs in the rings.
Ring C is the least bright of the three "classic" rings (A, B and C). Apparently, the substance is more dispersed there. The brightest is ring B, where the density of matter should be highest. In the B ring, the particles are located so densely that, having flown midway, we will lose sight of the stars.
In addition to the classical rings, the images transmitted by Voyager 1 show the D ring closest to the planet. It is believed that it was formed by material that penetrated the barrier that forms the inner edge of the C ring.
The F ring, judging by the images, may have a somewhat elliptical shape: some parts of this thin ring are located closer to the planet than other parts. This ring appears to be formed by two, perhaps three, loosely intertwined "strands." Scientists find it difficult to explain this phenomenon. One hypothesis is that because the F ring is made up of dusty particles, they could acquire an electrical charge from sunlight or solar-derived particles and become miniature electromagnets. In this case, their interaction with Saturn’s magnetic field can lead to the intertwining of the rings. Clumps of substance were found around the F ring. One of them was so dense that it was initially mistaken for a satellite. Subsequent analysis showed that this is a region of concentration of matter with a characteristic size of 100 - 200 km. It has been suggested that the wider portion of this clump is to some extent controlled by the satellites S-13 and S-14, or that the clump contains a large body from which pieces break off as a result of collisions, and therefore an increased density of material is observed in this area. The clumps appear to be moving in orbit around Saturn. It is assumed that the mentioned satellites S-13 and S-14, located on either side of the F ring, control the movement of particles in this ring.
Surveying the rings while scattering light forward revealed another ring, tentatively designated G. The orbital radius of the G ring is 150,000 km. It is believed to be located near the orbits of the “co-orbital” satellites S-10 and S-11. The shadow observed on one of these satellites may have been cast by this particular ring. The images also show the E ring, possibly extending up to 480,000 km from the planet.
In general, the ring system appears to be a relatively stable phenomenon for Saturn. In contrast, Jupiter's ring is believed to be a dynamic system that is constantly self-regulating but has a limited lifespan. The ring of Jupiter apparently exists due to the fact that some bodies continuously feed the ring with matter, or there are undetected bodies in the ring itself that generate particles. As for the rings of Uranus, relatively little is known about them.
Returning to the rings, among them there are narrow flows that deviate from a circular orbit. The edges of some rings are jagged, and they themselves sway under the gravitational pressure of satellites, bending and forming waves. Spiral waves, elliptical rings, strange interweaving of narrow rings... all the surprises of the rings are difficult to list.
What did Cassini learn?
The Cassini station was launched on October 15, 1997. In order to find itself in Saturnian orbit, Cassini had to perform a long-awaited and important braking maneuver. You can see part of this maneuver in this table of images.
The maneuver was carefully calculated long ago, and the entire action program was stored in the memory of the on-board computer. And now the long-awaited day, July 1, 2004, which designers and scientists had been waiting for, has arrived. At 2:11 GMT, Cassini passed the so-called ascending node of the trajectory and overcame the plane of Saturn's rings, slipping exactly between the two thin outer rings, designated F and G. |
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Isn't it impressive? (even such small images). At the moment, the Cassini spacecraft has already received a lot of images and information about the planet, and about the rings, and about the satellites of Saturn.
Origin of Saturn's rings For a long time it was believed that a careless satellite approached Saturn and was torn to shreds by its tidal forces. But Voyager data refuted this popular belief. It has now been established that the rings of Saturn (and other planets too) are the remains of a huge circumplanetary cloud many millions of kilometers long. |
Saturn is one of the most mysterious planets for both professional astronomers and amateurs. Much of the interest in the planet comes from the distinctive rings around Saturn. Although they are not visible to the naked eye, the rings can be seen even with a weak telescope.
Saturn's mostly ice rings are held in orbit by the complex gravitational influences of the gas giant and its moons, some of which actually lie within the rings. Although people have learned a lot about rings since they were first discovered 400 years ago, this knowledge is constantly being added to (for example, the most distant ring from the planet was discovered only ten years ago).
1. Galileo Galilei and Saturn
In 1610, the famous astronomer and "enemy of the church" Galileo Galilei was the first person to point his telescope at Saturn. He noted strange formations around the planet. But because his telescope was not powerful enough, Galileo did not realize that these were rings.
2. Billions of ice chunks
Saturn's rings are made up of billions of pieces of ice and rock. The sizes of these debris range from a grain of salt to a small mountain.
3. Only five planets
As you know, a person can see five planets with the naked eye: Mercury, Venus, Mars, Jupiter and Saturn. To see Saturn's rings and not just a ball of light, you'll need a telescope with at least 20x magnification.
4. The rings are named in alphabetical order
The rings are named in alphabetical order based on their date of discovery. The D ring is closest to the planet, and then as it moves away - the C, B, A, F, Janus / Epimetheus, G, Pallene and E rings.
5. Remains from comets and asteroids
Saturn's rings are believed by most scientists to be remnants from passing comets and asteroids. Scientists came to this conclusion because about 93% of the mass of the rings is ice.
6The Man Who Defined Saturn's Rings
The first person to actually see and define the rings of Saturn was Dutch astronomer Christiaan Huygens in 1655. At that time, he suggested that the gas giant had one hard, thin and flat ring.
7. Saturn's moon Enceladus
Thanks to the geysers that abound on the surface of Saturn's moon Enceladus, the icy ring E was formed. Scientists have very high hopes for this satellite, because it has oceans in which life may be hidden.
8. Rotation speed
Each of the rings rotates around Saturn at different speeds. The speed of rotation of the rings decreases with distance from the planet.
9. Neptune and Uranus
Although Saturn's rings are the most famous in the solar system, three other planets boast rings. We are talking about the gas giant (Jupiter) and the ice giants (Neptune and Uranus).
10. Perturbations in rings
The planet's rings may provide evidence of how comets and meteors passing through the solar system are attracted to Saturn. In 1983, astronomers discovered disturbances in the rings that resembled ripples. They believe this was caused by debris from the comet colliding with the rings.
11. Clash 1983
A 1983 collision with a comet weighing between 100 billion and 10 trillion kilograms disrupted the orbits of the C and D rings. It is believed that the rings will "align" over hundreds of years.
12. Vertical “bumps” on the rings
Particles inside Saturn's rings can sometimes form vertical formations. It looks like vertical "bumps" on rings about 3 km high.
13. Second after Jupiter
Apart from Jupiter, Saturn is the fastest rotating planet in the solar system - it completes a full rotation on its axis in just 10 hours and 33 minutes. Because of this speed of rotation, Saturn is more bulbous at the equator (and flattened at the poles), which further accentuates its iconic rings.
14. F Ring
Located just outside Saturn's main ring system, the narrow F ring (actually three narrow rings) appears to have curves and clumps in its structure. This led scientists to assume that there may be mini-moons of the planet inside the ring.
15. Launch 1997
In 1997, the Cassini automatic interplanetary station was launched to Saturn. Before entering orbit around the planet, the spacecraft flew between the F and G rings.
16. Tiny satellites of Saturn
Two gaps or fissures between the rings, namely the Keeler gap (35 km wide) and Encke gap (325 km wide) contain Saturn's tiny moons. It is assumed that these gaps in the rings were formed precisely due to the passage of satellites through the rings.
17. The width of Saturn's rings is enormous
Although the width of Saturn's rings is enormous (80 thousand kilometers), their thickness is comparatively very small. As a rule, it is about 10 meters and rarely reaches 1 kilometer.
18. Dark stripes running across the rings
Strange ghost-like formations have been discovered in the rings of Saturn. These formations, which look like light and dark stripes running across the rings, are called “spokes.” Many theories have been put forward regarding their origin, but there is no consensus.
19. Rings of Saturn's moon
Saturn's second largest moon Rhea may have its own rings. They have not yet been discovered, and the existence of rings is assumed based on the fact that the Cassini probe detected the deceleration of electrons in the magnetosphere of Saturn in the vicinity of Rhea.
20. Minimal weight of rings
Despite the apparent huge size, the rings are actually quite “light”. More than 90% of the mass of all matter in Saturn's orbit comes from the largest of the planet's 62 moons, Titan.
21. Cassini division
The ring rotates in the opposite direction.
Astronomers recently discovered a new, huge ring around Saturn, called the Phoebe ring. Located between 3.7 and 11.1 million km from the planet's surface, the new ring is tilted 27 degrees compared to the other rings and rotates in the opposite direction.
24. A billion planets like Earth can fit in the ring.
The new ring is so sparse that you can fly through it without noticing a single piece of debris, despite the fact that the ring could fit a billion planets like Earth. It was discovered by chance in 2009 using an infrared telescope.
25. Many of Saturn's moons are icy
Due to recent discoveries made in 2014, scientists believe that at least some of Saturn's moons may have formed within the planet's rings. Since many of Saturn's moons are icy, and ice particles are a major component of the rings, it has been hypothesized that the moons formed from distant rings that pre-existed.
For everyone interested in astronomy -.
