Saturn moves slowly, so people regard it as a symbol of mastering time and destiny. In Roman mythology, it was called the second generation God Cronus, who ascended the throne of God after overthrowing his father. No matter in the east or the west, Saturn is closely related to human agriculture, and the symbols expressed in astronomy are like a scythe that dominates agriculture.
Before 178 1 discovered Uranus, people thought Saturn was the farthest planet from the sun. Saturn can be seen in the telescope, which is surrounded by a beautiful ring of light. Saturn has more moons. Up to 1978 and 10 have been discovered and confirmed, and new discoveries have been made one after another.
Saturn is like Jupiter in many ways. For example, it is a giant planet with a volume of 745 times that of the Earth and a mass of 95. 18 times that of the Earth. Among the nine planets in the solar system, Saturn is second only to Jupiter in size and mass. Like Jupiter, it is surrounded by colorful clouds and guarded by more satellites. It is oblate because it rotates very fast. The equatorial radius is about 60,000 kilometers. The average density of Saturn is only 0.70g/cm ~ 3, which is the lowest among the eight planets. If you put it in water, it will float on the water. Saturn's large radius and low density make its surface gravity acceleration close to that of the earth. Saturn's brightness when it hits the sun can be compared with that of the brightest star in the sky. Because the plane of the halo does not coincide with Saturn's orbital plane, and the direction of the halo plane is unchanged when it runs around the sun, the apparent area of the halo is not fixed from the earth, so the apparent brightness of Saturn also changes. When the visible area of Saturn's rings is the largest, Saturn appears brighter; When the line of sight coincides with the plane of the halo, the halo appears as a straight line, and Saturn appears darker. The brightness difference between them is about 3 times.
Saturn's orbit around the sun has a radius of about 65.438+0.4 billion kilometers, and its orbit is oval. Its distance from the sun is about1.500 million kilometers at perihelion and apohelion. The average speed of Saturn's revolution around the sun is about 9.64 kilometers per second, and its period of revolution is about 29.5 years. Saturn also has four seasons, but each season lasts for more than seven years, because it is far from the sun, and it is extremely cold even in summer. Saturn's rotation speed is very fast, but the rotation speed at different latitudes is different, which is greater than Jupiter's. The rotation period on the equator is 18 hours 14 minutes, which becomes 10 hour and 40 minutes at 60 degrees latitude. That is to say, on Saturn's equator, there are only 10 hours and 14 minutes in a day and night.
Saturn's atmosphere is mainly composed of hydrogen and helium, and contains methane and other gases. Clouds of dense ammonia crystals float in the atmosphere. From a telescope, these clouds form parallel stripes like Jupiter's clouds, but they are not as bright as the Wood Nebula, but they are much more regular than the Wood Nebula. Saturn's cloud belt is mainly golden yellow, and the rest are orange and light yellow. Saturn's surface is as unstable as Jupiter's. The airflow near its equator is consistent with its rotation direction, and the speed can reach 500 meters per second, which is much larger than the wind on Jupiter.
Saturn is green near the polar regions, which is the darkest area on the whole surface. According to infrared observation, cloud top temperature is-170℃, which is 50℃ lower than Jupiter. Saturn's surface temperature is about-140℃. White spots sometimes appear on Saturn's surface. The most famous white spot was found in August 1933. This white spot appears in the equatorial region, which is egg-shaped and reaches 1/5 of Saturn's diameter. After that, the white spot continued to expand and almost spread to the entire equatorial belt.
Due to the low surface temperature and high escape speed (35.6 km/s), Saturn retained all the hydrogen and helium when it was formed billions of years ago. Therefore, scientists believe that studying the current composition of Saturn is equivalent to studying the original composition of the early solar system, which is very helpful for understanding the internal activities and evolution of the sun. It is generally believed that Saturn's chemical composition is similar to Jupiter's, but its hydrogen content is less. Saturn has more methane than Jupiter, but less ammonia.
1In April, 1973, pioneer of interplanetary probe 1 1 launched by the United States discovered that Saturn has an extensive ionosphere composed of ionized hydrogen, and its upper temperature is about 977℃. Observations show that there are auroras in Saturn's polar regions.
At present, it is believed that when Saturn was formed, it was initially the accretion of soil and ice, followed by the accumulation of gas. So Saturn has a core with a diameter of 20,000 kilometers. This core accounts for 10% to 20% of Saturn's mass. The core is surrounded by an ice shell with a thickness of 5,000 kilometers and a metal hydrogen layer with a thickness of 8,000 kilometers. In addition to metallic hydrogen, there is an extensive molecular hydrogen layer.
1969, an airplane made an infrared observation of Saturn's thermal radiation in the upper atmosphere of the earth, and found that Saturn, like Jupiter, radiated twice as much energy as it received from the sun. This shows that Saturn and Jupiter have the same internal energy. Later, the infrared detection of Pioneer 1 1 confirmed this point, and it was measured that the energy emitted by Saturn was 2.5 times that absorbed from the sun.
Rings of Saturn
16 10, Italian astronomer Galileo observed strange appendages beside Saturn's sphere. 1659, the Dutch scholar huygens proved that this is a halo that leaves the ontology. 1675, Italian astronomer Cassini discovered a hidden seam in the middle of Saturn's rings, which was later called Cassini's ring seam. He also guessed that the halo was made up of countless small particles. Spectral observations more than two centuries later confirmed his guess. But in these two hundred years, Saturn's rings are usually considered as one or several flat disks of solid matter. Until 1856, the British physicist Maxwell theoretically demonstrated that Saturn's ring is a material system in which countless small satellites revolve around Saturn on Saturn's equatorial plane.
Saturn's rings lie on Saturn's equatorial plane. Before space exploration, Saturn was observed to have five rings from the ground, including three main rings (A ring, B ring and C ring) and two dark rings (D ring and E ring). B ring is wide and bright. It has a C ring on the inside and an A ring on the outside. Between ring A and ring B is a Cassini seam about 5000 kilometers wide, which was discovered by astronomer Cassini in 1675. The inner radius of ring B is 9 1 1,500 km, the outer radius is116,500 km, and the width is 25000km, so two earths can be placed side by side. The inner radius of ring A is 12 1 500 km, the outer radius is 137000km, and the width is1550km. C ring is very dark. It extends from the inner edge of ring B to the place only 12000 km away from Saturn's surface, and its width is about 19000 km. 1969, a darker D ring was found inside the C ring, which almost touched the surface of Saturn. There is also an E ring outside the A ring, which is composed of very sparse material fragments and extends beyond five or six Saturn radii. 1In September 1979, Pioneer 1 1 detected two new rings-F ring and G ring. The F ring is very narrow, with a width of less than 800 kilometers. The distance from the center of Saturn is 2.33 Saturn radii, just outside the A ring. G ring is far away from Saturn, and it is distributed in a vast area between about 10 and 15 Saturn radius from Saturn center. "Pioneer" 1 1 also measured the positions and widths of the A-ring, B-ring, C-ring and Cassini seam, and the results were not much different from the ground observations. The ultraviolet glow observation of Pioneer 1 1 found that there were huge hydrogen clouds around Saturn's visible ring. The ring itself is the source of hydrogen clouds.
Except for ring A, ring B and ring C, all other rings are weak. Saturn's equatorial plane and orbital plane have a large inclination. Seen from the earth, Saturn swings in the north-south direction, resulting in periodic changes in the shape of Saturn's rings. After careful observation, it is found that there are several cracks in Saturn's ring besides Cassini cracks, all of which are areas with low particle density, but most of them are incomplete and temporary. Only the Cohen seam in the A-ring is permanent, but the circumferential seam is incomplete. Scientists believe that these annular cracks are caused by the gravitational vibration of Saturn's moons, just as Jupiter's huge gravitational perturbation caused the kirkwood cracks in the asteroid belt. Pioneer 1 1 found a new ring joint between ring a and ring f, which is called pioneer joint. The measured width of Cohen joint is 876 kilometers. The nature of Saturn's rings is made clear by observation, thanks to American astronomer Keeler, who found from the Doppler shift of the light reflected from 1895 Saturn's rings that Saturn's rings are not solid disks, but a large group of particles that revolve around Saturn in independent orbits. The occultation of Saturn's rings does not completely block the masked starlight, which also shows that Saturn's rings are composed of separated particles. 1972 the radar echo reflected by Saturn's rings shows that the particles in the rings are ice cubes with a diameter of 4 to 30 cm.
Scientists were very surprised by the photos of Saturn sent back by the probe. Saturn's rings seen nearby turned out to be a large piece of gravel and ice, which made people see things in a blur. Their diameters range from a few centimeters to dozens of centimeters, and only a few of them exceed 1 meter. There are hundreds to thousands of rings on the torus around Saturn, with different sizes and shapes. Most rings revolve symmetrically around Saturn, but there are also asymmetric, complete, relatively complete and incomplete rings. The shape of the ring is serrated and radial. What puzzles scientists is that some annual rings seem to be thick ropes that are loosely twisted together, or twisted together like girls' braids. The radiation ring has opened scientists' eyes and made them stupid. The material that makes up the halo rotates synchronously around Saturn like a wheel. Isn't it required that the farther away from the rubble and ice, the faster the movement? This obviously violates the laws of material movement that have been mastered at present. So, what law is at work? It is still being explored.
Saturn's interior is similar to Jupiter's, with a rock core. Outside the core is a shell composed of 5000 kilometers of ice and 8000 kilometers of metallic hydrogen, and the outermost layer is surrounded by colorful clouds. Saturn's atmospheric movement is relatively calm, and its surface temperature is very low, about-140 degrees Celsius.
Saturn rotates obliquely around the sun at an average speed of 9.64 kilometers per second. Its orbit radius is about 65.438+0.4 billion kilometers, and its revolution speed is slow. It takes 29.5 years to go around the sun, but the rotation speed is very fast. The rotation period on the equator is 654.38+00 hours and 654.38+04 minutes.
Saturn's moons
Saturn's beautiful optical ring is made up of countless small celestial bodies, which revolve around Saturn on Saturn's equatorial plane. Saturn is also the planet with the largest number of satellites in the solar system. There are many large and small satellites around it, just like a small family. So far, a total of 23 have been found. The various shapes of Saturn's moons have aroused great interest among astronomers. Titan, the most famous satellite, has an atmosphere, and it is the only celestial body with an atmosphere among the solar system satellites found so far.
Saturn has at least 18 satellites, 9 of which were discovered 1900 years ago. Enceladus to Enceladus are arranged from Saturn near to far: Enceladus, Enceladus, Enceladus, Enceladus, Enceladus, Titan, Enceladus, Titan, Enceladus, Enceladus, Enceladus. The distance between Enceladus and Saturn is only159500km, which is only 2.66 times of Saturn's equatorial radius, and it is close to roche limit. These satellites revolve around Saturn in a nearly circular orbit near Saturn's equatorial plane.
1980, when Voyager flew over Saturn, eight new satellites were discovered on the basis of the original nine satellites (Enceladus, Enceladus, Enceladus, Enceladus, Titan, Titan and Enceladus). But it's hard to say how many moons Saturn has. Some of the larger particles that make up Saturn's rings may actually be small satellites. Saturn has the most satellites in the solar system. Unlike Jupiter's moons, Saturn's moons cannot be classified simply by composition and density. The satellites discovered by Voyager show complex and diverse features.
Some areas of Enceladus and Rhea are very rugged, while others are much flatter. The white stripes on the surface indicate that water once appeared on these two satellites. Among Saturn's many moons, Titan, one of the largest moons in the solar system, is of most interest to us. Voyager scientists were surprised to find that it has a thick atmosphere, which is 60% denser than the earth's atmosphere. Titan is very cold, and its surface temperature is about-150℃. At this temperature, methane exists in three states: gas, liquid and solid. Clark Chapman, a planetary scientist, said, "The methane on Titan may be like water at 0℃ on Earth." "through the muddy area of the arctic, we can vaguely see the surface landscape of titan ... most rocks composed of methane and ammonia ice cubes are buried under viscous oil layers. For a long time, tiny dust particles in tar smoke kept gathering ... Titan's thick liquid methane and ocean were blocked by suffocating methane ice fog. " The tiny Titan has a scar, which is one of the most obvious scars in the solar system. A huge crater shows that it suffered a heavy blow and almost split it in two. The diameter of this huge crater, which has been hit hard, is about one third of that of the whole planet. Its surface is so pitted that the ice is cut into pieces. Walking on its surface is like walking on a huge snow cone.
Enceladus has a fault system and a large area that has never been hit by meteorites. The heating of continental tides may have played an important role in the process of surface reconstruction. This activity seems to have happened only recently, and it can also be used to explain why its surface is dazzling. Enceladus reflects almost all the light, and its frozen surface may be covered by water from the inside.
Partos is bright on one side and dark on the other. The bright side can reflect about half of the illuminating light, while the other side is almost dark. Black matter may contain organic carbon, one of the basic components of life.
Titan looks like a fragment of a larger object. Its irregular shape and extremely uneven surface make it look like a slightly larger asteroid. Fragments of this satellite may have entered Saturn's rings by now.
Titan also survived the obvious cosmic violence. A huge canyon extends from one end of the satellite to the other. This long and narrow valley seems to be caused by internal forces. The pressure of internal solidification and expansion leads to cracks on its surface. Scientists can't explain how a satellite composed of at least 80% water ice can withstand such geological activities.
The results of the voyager probe make people believe that it once dominated Saturn's early history. Saturn's moons look like survivors of endless explosions. Their bright frozen surfaces have been damaged by countless meteorites. But one of the satellites is very similar to the early earth. Maybe one day, Titan with a thick atmosphere can evolve tenacious life.
Lighter than water.
Saturn, like other planets, orbits the sun in an elliptical orbit. Saturn's orbital radius around the sun is about 9.54 astronomical distance units (about 65.438+0.4 billion kilometers), the orbital eccentricity is 0.056, the included angle between the orbital plane and the ecliptic plane is 2.5', it takes about 29.5 years to orbit the sun, and the average revolution speed is about 9.6 kilometers per second. Saturn's rotation speed is very fast, second only to Jupiter, and its rotation speed varies with latitude. The rotation period on the equator is 10 hour 14 minutes, and at latitude 60, it is 10 hour and 40 minutes. Because of its rapid rotation, its shape is flattened, which makes it the flattest in planets of the solar system. Saturn's surface also has stripes extending along the equator, and its surface is covered by clouds.
Observing Saturn with an astronomical telescope, you see a celestial body with a halo. Saturn's equatorial radius is about 60 thousand kilometers, and the difference between equatorial radius and polar radius is more than 5000 kilometers. Its volume is 740 times that of the earth and its mass is 95 times that of the earth. Among the planets in the solar system, Saturn is second only to Jupiter in mass and size. The average density is 0.7 g/cm3, which is less than that of water. Because Saturn's density is too small, its surface gravity acceleration is similar to that of the earth (1.07 of the earth). On Saturn, an object can leave Saturn at a speed of 37 km/s, which is much faster than the surface of the earth, so Saturn can bind many atmospheres.
Saturn has a dense atmosphere, which is mainly composed of hydrogen and helium, as well as methane and ammonia. Through the astronomical telescope, we can see that Saturn's surface also has some alternating stripes parallel to its equatorial plane, and sometimes bright spots, dark spots or white spots appear in the stripes. The appearance of white spots is not very stable. The most famous white spot was discovered by British astronomer W T Hayward with a small telescope in August 1933. This white spot is located in Saturn's equatorial region, and it is egg-shaped with a length of 65438+ 0.5 of Saturn's diameter. Later, this white spot gradually expanded and almost spread to Saturn's equatorial belt.
In order to explore the physical conditions of the outer space of the solar system, the pioneer1/kloc-0 was launched in April 1973, and flew to Saturn in September 1979, becoming the first artificial celestial body to explore Saturn nearby. Voyager 1 and Voyager 2, after checking Jupiter, continued to sail to Saturn to check Saturn. After completing the mission of exploring Saturn, Voyager 2 went on to visit Uranus and Neptune. These "multi-mission" spacecraft have brought us new news about Saturn.
The "Pioneer 1 1" spacecraft was found in August and September of 1979 at a distance of 0/280,000 km from Saturn/Kloc-0. Saturn's magnetic field is very special. Its magnetic field map is like a big whale, with a blunt head, flat wings on both sides and a thick tail. The magnetic axis of Saturn's magnetic field coincides with its rotation axis, and the magnetic core deviates from Saturn's core by 22.5 kilometers. The magnetic field is thousands of times larger than the earth's, but smaller and less complicated than Jupiter's.
Saturn's surface temperature is-140℃, and its zenith temperature is-180℃, which is 50℃ lower than Jupiter's. Saturn has a rock core with a diameter of 20,000 kilometers, and outside the core is Saturn's atmosphere.
Saturn family
Before the spacecraft explored Saturn, people knew that Saturn had 10 satellites. Titan was discovered in 1977. Pioneer 1 detected the twelfth satellite when 1979 flew to Saturn. In order to commemorate its achievements, it was named "Pioneer". Voyager 1 discovered five more satellites during the close inspection of Saturn on 19801October 26th and 101October 26th. 1981On August 25, 2000, Voyager 2 passed over Saturn's clouds 10 1000 km, and made an investigation of Saturn, its rings and nine satellites. During this flight over Saturn, six more satellites were discovered.
There are 23 confirmed Saturn moons. The closest to Saturn is Titan XV, whose distance from Saturn is137,000 km, and the radius from the satellite to the center of Saturn is only 2.29 Saturn. Period of revolution is 0.60 1 day, and its radius is only15km. The farthest is Saturn IX, with an average distance of about 654.38+029.3 thousand kilometers, and its distance from Saturn center is 265.438+06 Saturn radius. The angle between the orbital plane of Partos and the equatorial plane of Saturn is 7 52', which is an irregular satellite. The intersection angle between Titan's orbital plane and the equatorial plane of the upper star is 175, and it is retrograde, with an orbital eccentricity of 0. 163, which also belongs to an irregular satellite. The remaining satellites are conventional satellites. Interestingly, Enceladus and Enceladus, Enceladus and Enceladus are all in the same orbit. Titan, Titan and Titan are three stars living in the same orbit. Judging from the data sent back by the spacecraft, no traces of volcanic activity were found on these satellites.
Among Saturn's moons, Titan is one of the celestial bodies that astronomers pay attention to. It was discovered by the Dutch astronomer Huygens in 1655. For a long time, Titan has been regarded as the largest satellite in the solar system and the only satellite with an atmosphere, and its atmospheric composition is mainly methane. In the past, people thought that its surface temperature was not very low, so people speculated that there might be life on it. The data sent back by Voyager 1 is disappointing. It found that Titan's diameter is only 5 150 km, which is not the largest satellite in the solar system (Ganymede has the largest diameter of 5262 km). It has a dense atmosphere and a liquid surface. Its atmosphere is at least 400 kilometers thick and its methane content is less than 1%. Titan's surface temperature is between-18 1℃ and -208℃, and there are ice curtains and rock cores under the liquid surface. The spaceship found no trace of life. Titan can emit radio waves, which makes people puzzled. In addition, there is a hydrogen cloud near Titan's orbit.
Except for Titan, the data sent back by astronomers from the Voyager spacecraft found that Saturn's other satellites are relatively small, with meteorite scars on the cold surface, like broken eggshells. There is a crater with a diameter of 128 km on the surface of Enceladus. Enceladus has desolate plains, craters and folded ridges, and its different regions represent different historical periods; There is a deep and wide rift valley about 800 kilometers long on Titan. There are sparse and bright stripes on Titan's surface, which are all around the crater.
Visit the giant goddess
1655 On March 25th, Dutch astronomer Huygens accidentally discovered a satellite of Saturn, which was named Titan, while observing Saturn with a self-made 3.7m long refracting telescope. Titan is the wife of Cronus, a giant goddess in Greek mythology, and also the second generation god. What attracts astronomers' attention most is Titan, the first Saturn satellite discovered by human beings.
Titan has long been regarded as the largest satellite in the solar system, bigger than Mercury. Voyager's close-range survey took five high-resolution photos at a distance of 35 kilometers. Titan in the photo shows a beautiful orange-red star, just like a ripe orange. More importantly, the received data rewrote Titan's original diameter of 5,800 kilometers, and the actual diameter should be 4,828 kilometers. It was forced to transfer the title of "King of Satellites" to Jupiter's moon Ganymede, ranking second. This has not affected its status. Scientists have always been interested in Titan because it is the only celestial body in the satellite with an atmosphere. The main component of the atmosphere is nitrogen, accounting for about 98%, methane accounting for 1%, and the remaining hydrocarbons account for a very small proportion in the atmosphere, with an atmospheric thickness of about 2700 kilometers. Titan's surface temperature is very low, ranging from-190℃ to -2 10℃, and it is a beautiful sea of liquid nitrogen.
Although we can't see the surface of Titan, the information provided by Voyager shows that Titan is another strange world in the solar system, with a dark and cold surface, a sea of liquid nitrogen, a dark red sky and nitrogen rain occasionally mixed with hydrocarbons. These are ideal places for human beings to understand the origin of life and various chemical reactions.
It has been more than 300 years since Huygens discovered Titan, and Titan is still a mystery to be solved. If you want to have a deeper understanding of Titan, you need human beings to continue to explore.
Outstanding "talents"
Why do astronomers pay special attention to Titan? Titan is favored and valued by astronomers because of its outstanding talent. Titan's unique "talent" is manifested in the following aspects:
First of all, Titan has a diameter of 4,828 kilometers, ranking second in the satellite world, much larger than Pluto in the nine rows and almost as big as Mercury. Its mass is 1.8 times that of the moon, its average density is 1.9 grams per cubic centimeter, which is about 1/3 of that of the earth, and its gravity is 14% of that of the earth.
The average distance between Titan and Saturn is 6.5438+0.22 million kilometers, and it orbits Saturn in a nearly circular orbit. Like the moon, it always faces its planet Saturn in the same direction. In other words, if you look at Titan from Saturn, you will always see only the same half of Titan. Its orbit is basically on Saturn's equatorial plane. You can think about it. It is hard to imagine that a celestial body as big as Titan runs in a nearly perfect orbit with a radius of about 654.38+0.22 million kilometers. It's not easy to draw such a circle. It shows the natural wonders in the evolution of celestial bodies.
Secondly, in 1944, the Dutch-American astronomer kuiper made a systematic spectral observation of Titan, and found that there was methane gas on Titan, thus confirming the existence of a dense atmosphere on Titan. Until now, Titan is still the only satellite with an atmosphere among more than 60 satellites known in the solar system. How can this not be particularly favored by astronomers?
Thirdly, according to the movement characteristics, physical condition and chemical composition of Titan, astronomers determined that Titan evolved with Saturn, belonging to a stable satellite, and could not be a small celestial body captured by Saturn later. At one time, some astronomers compared Titan's celestial characteristics and celestial environment with that of the Earth, such as mass, volume, surface gravity, surface temperature, atmospheric composition, water and ice content, rotation and revolution, in order to obtain clues about the evolution of early life materials.
Is there life on other celestial bodies? This question has been haunting astronomers' minds. Huygens, the discoverer of Titan, wrote in his book "Wonders of Celestial Bodies, Speculation on Residents, Plants and Their Worlds on Other Planets": If we think that there is nothing on these celestial bodies except endless desolation, …
It is very unreasonable to even think that there can be no advanced creatures there, so we belittle them. It is true that judging whether there is life on any celestial body is a very serious scientific problem. At present, I am afraid it is unrealistic to be too optimistic, but it is also unfounded to be too pessimistic. Practice is the only criterion for testing truth. As for the life information on Titan, it is still a mystery that is not optimistic, but it will be answered in the practice of continuous exploration.
Seen from the earth, Titan is an 8.4-magnitude star. You can't see it directly with your eyes. With a good telescope, you can only see a little red dot-shaped disk. Why this color? Some people think that this may be because there are complex organic molecules on Titan. Of course, relying entirely on ground observation can't solve such problems, and it can only be "an armchair strategist".
With the rapid development of space industry, interplanetary probes have made unprecedented achievements. At present, two interstellar spacecraft have personally detected Titan. They are the pioneer of American launch 1 1 and Voyager 1.
September 1979, 1, Pioneer 1 1 flew over Saturn and visited Titan. However, when Pioneer 1 1 visited Titan, a strong solar wind was catching up, which seriously affected the information sent back. The ground control center only received five high-resolution photos taken at a distance of 350,000 kilometers. In the photo, Titan appears beautiful orange-red, just like a ripe orange. Voyager 1 flew to Titan in June1980+065438+1October1. When it was closest to Titan, it was only 4000 kilometers away from the cloud top, and the exploration was a complete success. It was this time that the diameter of Titan was measured as 4,828 kilometers instead of 5,550 kilometers as previously thought.
Voyager 1 Investigation on Titan shows that Titan does have a thick atmosphere, about 2700 kilometers thick, which is higher than the density of the earth's atmosphere. The main components of the atmosphere are nitrogen, accounting for 98%, methane accounting for 1%, and a small amount of ethane and hydrogen. There is also nitrogen in the atmosphere of Venus, Earth and Mars, but not as much as Titan.
Voyager 1 also found that Titan's atmosphere is foggy. The dense fog layer prevented sunlight from reaching the surface of Titan, which affected the observation of the surface of Titan by travelers 1. At the same time, some scientists believe that Titan's atmosphere is full of methane according to the observation data of Voyager 1.
In order to further study the relationship between Titan's atmosphere and life, carl sagan, a planetary physicist at Cornell University in the United States, conducted a simulation experiment on Titan's atmosphere. Researchers believe that Titan's atmosphere contains a lot of nitrogen, which produces a variety of pre-life chemicals. Sagan pointed out: "A similar process may have happened on the early earth. However, the pre-life chemical process that happened on Titan is probably lifeless, because the temperature there is far below the freezing point of water. "
Speaking of which, have you ever wondered: Why is Titan the only satellite with such a rich atmosphere? This has always been a question that planetary physicists are thinking about. Some people think that this may be because Titan's surface temperature is high enough to maintain a considerable amount of methane and ammonia to keep the ice on its surface in equilibrium. It is also possible that the ice on Titan contains methane and ammonia, and it is easy to form an atmosphere at Saturn's temperature. The third possibility is that Titan's atmosphere will not escape like Jupiter's strong magnetic field. The fourth possibility is that Titan is massive and can differentiate internally. The differentiated ice is concentrated on the surface, and its gravity is enough to prevent most of the gas from escaping.
What is the surface of this fascinating Titan? It should be said that there is no intuitive information so far. Scientists have made many possible speculations, and the description of Titan by science fiction writers is even more wonderful. However, everything should respect science.
According to the nitrogen content in Titan's atmosphere, the surface temperature of Titan is much lower than that of the Earth, ranging from -20 1 to-190℃, and the volume and mass of Titan. Some scientists speculate on its internal physical conditions and surface characteristics, and first look for the proportional relationship between rocks and ice on Titan. It is estimated that the rock material on Titan accounts for about 55% of its total mass, and the rest is ice. Titan's surface is an icy liquid ocean. The ocean consists of 70% ethane, 25% methane and 5% dissolved nitrogen. The entire liquid ocean is about 1 km thick and surrounds Titan. 1on June 4-5, 989, radar detection was carried out from the earth to Titan, and the results showed that there might be land areas on Titan.
Voyager 1 also found that the light and shade of Titan's northern hemisphere are different: the southern hemisphere is bright and the northern hemisphere is dark. What caused this? It may be caused by the different seasons on Titan. When Voyager 1 visited, Titan's northern hemisphere was just in beginning of spring. However, some people think that this may be the influence of Saturn's magnetosphere on Titan. Anyway, it's still unclear. Titan's atmosphere has a strong light absorption capacity, which can absorb about 80% of the sunlight falling on it. Most of this heat is absorbed by fog particles and methane gas in the atmosphere, and perhaps only 5% ~ 10% of solar energy reaches the surface of Titan.
Since Huygens discovered Titan, there seem to be more and more mysteries about Titan for more than 300 years. In fact, this is not surprising, which shows that our understanding is getting deeper and deeper. Copernicus, a great Polish astronomer, famously said, "Man's bounden duty is to be brave in exploration."