What is the planet called Ying in ancient times?

Basic information about Mars

Mars is one of the eight planets, ranking fourth in the order from near to far from the sun. To the naked eye, Mars is a striking lux star, moving slowly among the stars. On the earth, it sometimes advances and sometimes retreats, and its brightness often changes. At the darkest time, the apparent magnitude is+1.5, and at the brightest time it is much brighter than Sirius, reaching -2.9. Because Mars is as bright as fire, its brightness changes frequently and its position is not fixed, so China called Mars "sparkling" in ancient times. In ancient Roman mythology, Mars was compared to the god of war in Mars mythology, who was covered in armor and blood. In Greek mythology, Mars is also regarded as the god of war. Sometimes Mars is also called "Red Planet".

Mass 6.421e+23kg.

The equatorial radius is 3397.2 kilometers.

The average density is 3.94 g/cm3.

The average daily driving distance is 227.94 million kilometers.

The rotation period is 24.6229 hours.

Period of revolution 686.98 days.

The equatorial surface gravity is 3.72 m/s 2.

The equatorial escape velocity is 5.02 km/s.

Minimum surface temperature-140℃

Average surface temperature -63℃

The maximum surface temperature is 20℃

Atmospheric pressure 0.007 bar

Atmospheric composition: carbon dioxide 95.32%, nitrogen 2.7%, argon 1.5%, oxygen 0. 13%, carbon monoxide 0.07%, water 0.0009 1% and others 0.0000.

The soil on the surface of Mars contains a lot of iron oxide. Due to long-term exposure to ultraviolet rays, iron will form a layer of red and yellow oxides. To exaggerate, Mars is like a world full of rust. Because Mars is far away from the sun, it receives only 43% of the solar radiation energy of the earth, so the average temperature on the ground is about 30 degrees Celsius lower than that of the earth, and the temperature difference between day and night can reach hundreds of degrees Celsius. Near the equator of Mars, the highest temperature can reach about 20℃. Depending on the season and place, the surface temperature of Mars ranges from minus 87 degrees Celsius to minus 5 degrees Celsius. Mars also has an atmosphere. Its main component is carbon dioxide, accounting for about 95%, and a very small amount of carbon monoxide and water vapor.

Mars is smaller than the Earth, with an equatorial radius of 3,395km, which is half of the Earth's. Its volume is less than 1/6 of the Earth's, and its mass is only110 of the Earth's. Like the earth, Mars has the structure of core, mantle and crust.

The rotation of Mars is very similar to that of the Earth, with a rotation period of 24 hours, 37 minutes and 22.6 seconds. A day and night on Mars is a little longer than a day and night on Earth. Mars makes a revolution of about 687 days, and a year of Mars is about two years for the Earth.

The polar ice sheet of Mars is similar to that of the Earth. Winter is small and summer is big.

Mars has two satellites. One near Mars is called Phobos, and the other farther away is called Phobos. Because Mars is regarded as the god of war in Greek mythology, astronomers named its two moons after his two sons Phobos and Derris.

There are obvious seasonal changes on Mars, which is its main similarity with the Earth. But beyond that, Mars is very different from the Earth. The surface of Mars is a desolate world, and carbon dioxide in the air accounts for 95%. The dense carbon dioxide atmosphere causes high temperatures on Venus, but on Mars, the opposite is true. The atmosphere of Mars is very thin, and its density is less than 1% of that of the earth's atmosphere, so it is impossible to store heat. This causes the surface temperature of Mars to be extremely low, rarely exceeding 0℃. The lowest temperature at night can reach-123℃.

This is a global photo of Mars taken by NASA's Viking orbiter. You can clearly see the huge "Sailor Valley" in the picture. Sailor Valley is about 4000 kilometers long and 8 kilometers deep. (United States Geological Survey)

Mars is called the red planet, because its surface is covered with oxides, so it appears rust red. Most of the surface of Mars is desert, with a lot of red oxides, ochre gravel fields and solidified lava flows. There are often violent winds on Mars, which can raise dust and form a super-large sandstorm, which can cover the whole of Mars. Every sandstorm may last for weeks.

Water is contained in the ice sheets at the poles of Mars and in the atmosphere of Mars. The detection data obtained from the surface of Mars prove that in ancient times, there was liquid water on Mars, and the amount of water was particularly large. These waters converge into large lakes and even oceans on the surface of Mars. Now we can see many criss-crossing river beds on the surface of Mars, which may have been washed away by water at that time. In addition, many water-drop-shaped "islands" on the surface of Mars are also suggesting this to us.

Because of the similarity between Mars and Earth, Mars has always been considered as the possibility of extraterrestrial life. Recent scientific research shows that it is impossible to prove that there is life on Mars. On the contrary, there are more and more signs that Mars is more like a barren and dead world. Nevertheless, some evidence still points out that there may have been life on Mars. For example, the analysis of a meteorite from Mars found in Antarctica shows that there are some tubular structures similar to bacterial fossils in this stone. All these continue to interest people in the existence of life on Mars.

1976, American Viking 1 and Viking 2 Mars probe successfully landed on Mars for the first time, and returned tens of thousands of photos. That flight found no evidence of life on Mars. However, Schoultze Macuch, an American geologist, published a paper saying that at that time, the probe might have really discovered Martian creatures, but people didn't realize their existence at all, because the form of Martian creatures was too different from that of the earth's ecology. Human probes pour water into Martian soil, which may drown Martian life in another cell. In addition, the human probe also heated Saturn's soil, which may have roasted the Martian microorganisms to death.

Mars canal

This canal is an artificial river. If we admit that there are canals on Mars, it is tantamount to admitting that there is intelligent life on Mars, which is undoubtedly a question that arouses people's interest.

Italian astronomer Schia Parelli first pointed out that there are canals on Mars. 1877, he took advantage of the encounter between the perihelion of Mars and the earth to observe Mars with a telescope with a diameter of 24 cm, and found some fuzzy straight lines on the circular surface of Mars, which connected the dark spots. After continuous observation, he found that some dark lines were as long as 120 km, criss-crossing, forming a network covering the Martian continent. It is also found that the existing two dark lines are parallel to each other and have seasonal variations. He also charted his findings and made them public. At first, Parelli guessed that these dark lines were just waterways connecting the bay, but did not say that they were artificial canals. But in the 1980s of 19, his discovery attracted people's attention. Some people describe these hidden lines as canals dug by intelligent creatures, and this person is Lovel of the United States.

Lovel was fascinated by the discovery of Skia Parelli. In order to observe Mars, he built an observatory in Arizona at his own expense. After years of observation, it not only confirmed schiaparelli's discovery, but also discovered hundreds of new rivers, saying that the surface of Mars is as detailed as a "spider web". He also wrote his observations into three books: Mars, Mars and its Canal, and Mars-the Residence of Life. He believes that because the air on the surface of Mars is very thin, which leads to water shortage, the polar cap of Mars made of ice and snow begins to melt in summer and become a water source. The purpose of the waterway on Mars is to lead the water from the polar cap to the arid tropical areas to irrigate the fields there. Judging from these waterways, they all converge in the center of the mainland, which is obviously purposeful. Its black spot is an oasis.

Levaire's theory aroused people's great interest and quickly swept the world. However, Lovel's theory is not one-sided, and it is constantly challenged. For example, Bayod of the United States thinks that the dark lines on Mars are not straight, irregular and unconnected at all. Anthony Adi of Greece supports Barnard's view through his own observation, and thinks that describing the dark line on Mars as a canal is purely an illusion of the eyes, "belonging to people with too rich imagination."

Because of the appearance of the above viewpoint, the myth about Martians gradually declined, and the American Mariner 9 probe further proved that the existence of the Mars Canal was false. However, Mariner 9 made an unexpected discovery, that is, there are many geological structures similar to river beds on Mars, and their positions are quite different from those described by Levaire.

Some people divide the riverbed on Mars into three categories: flowing riverbed, outflow riverbed and erosion riverbed, which is very similar to the riverbed on Earth. They split up. About a long time ago, there was a warm climate on Mars, with atmosphere and precipitation on it, which ensured the existence of rivers. Later, Viking 1( 1976) not only confirmed the existence of canals on Mars, but also confirmed the existence of man-made buildings.

Shuishou valley

The largest canyon in the solar system cuts a wide hole on the surface of Mars. The majestic valley named Sailor Canyon stretches for more than 3,000 kilometers, and the widest point is more than 600 kilometers, about 8 kilometers. In contrast, the Grand Canyon in Arizona is about 800 kilometers long, 30 kilometers wide and 1.8 kilometers deep. Although there is a main hypothesis that when the planet cooled billions of years ago, a crack later evolved into the current canyon, the real cause of Mariner Canyon is still uncertain. Recently, we have determined several geological evolution processes in this canyon.

Mars landform

In the telescope, Mars presents a bright and fuzzy red round surface. The most striking thing is that the size of the white polar cap covering the polar regions changes with the seasons of Mars. In a larger telescope, you can also observe bright or dark areas that are linear for at least hundreds of kilometers: bright and orange areas are called "continents", accounting for almost five-sixths of the total area of Mars; Dark areas are called "oceans", and their colors often change with the seasons.

There are striking differences between the northern and southern hemispheres of Mars. As far as the geological history of Mars is concerned, the southern half is relatively old, with rugged surface and dense craters. It is estimated that most of these craters were formed in the early stage of the history of Mars (probably the first billion years); The northern half is characterized by a large volcanic lava plain, which is very similar to the "ocean" on the moon, and there are some extinct volcanoes. The terrain in the northern half is generally lower than that in the southern half, and there are much fewer craters than in the southern half. The height difference of the surface of Mars is generally about 5 ~ 10 km. The desert part of Mars is covered with red silicate, hematite, other iron oxides and other metal compounds, so it appears bright orange-red. These covers are all young materials, which may have originated from volcanoes or weathering.

The geographical features of the surface of Mars mainly include craters and volcanoes. Compared with the surface of the moon, the number of craters on Mars is much less, and the edges of craters are relatively gentle (the slopes are all less than 10), unlike craters on the surface of the moon, which cast sharp shadows, which indicates that craters have been seriously eroded. Craters can be divided into two types: volcanic craters and craters formed by meteorite impact. According to the standards of the earth's surface, many surface structures on the surface of Mars are huge. For example, the giant shield volcano on Mars is much bigger than that on Earth. On earth, the two Hawaiian volcanoes, Mauna Loa and Monaque Ya, add up to about 200 kilometers in diameter, 9 kilometers higher than the seabed, while the largest Olympus volcano on Mars is about 550 kilometers in diameter, 27 kilometers higher than the surrounding ground. There are also large volcanoes like this. They are located in the 2000km-long Tasis Highland, which is10km higher than the surrounding northern hemisphere plain. The shield volcano of Mars is similar in shape and structure to that of Hawaii. These craters used to be the outlet of lava. Lava flows down from the side of the volcano, forming a radial terrain extending from the center in all directions. Many volcanoes with a diameter of about 100 km are in different preservation states. They are scattered on the surface of Mars, mostly in the northern hemisphere. As for the crater formed by meteorite impact, the largest crater is Heiners Basin, with a width of1600km and a depth of at least 4km. In some parts of the southern hemisphere, the density of craters is similar to that of the bright highland ring mountains on the moon. It is speculated that they were formed at the same time, ranging from 4 billion to 4.5 billion years. These areas still retain the ancient surface. Due to the continuous coverage of lava flows in most parts of the northern hemisphere, the ancient surface no longer exists. Several craters on the plain are records of meteorite impacts after the formation of the plain.

The most striking feature on the surface of Mars is the huge canyon in the equatorial region. The largest one is Mariner Valley, which is located south of the equator. It is actually a series of canyons, extending more than 4000 kilometers in the equatorial region, 6 kilometers lower than the surrounding ground. Canyon walls are usually very steep, with obvious boundaries, and show signs of collapse and landslide activity. Some intricate canyons may be formed during the melting and evaporation of underground ice, or may be caused by wind or water erosion. The origin of the Grand Canyon is still unknown.

Today, Mars is a desolate world. There is no liquid water on the surface of Mars, but there are some wide and curved river beds on the surface of Mars. These riverbeds are completely different from the sensational "canal". The longest of these dry river beds is about 1 1,500 kilometers, and the width is 60 kilometers or more. The main river beds are distributed in the equatorial region. Satellite images show that the large riverbed and its tributaries combine to form a well-defined waterway system. At the same time, it also has teardrop-shaped islands, sandbars and woven patterns. Almost all the tributaries flow downhill. These riverbeds are different from the lava riverbeds on the earth and the moon, and must be caused by liquids that are less viscous than lava flows. This liquid is probably water. Today, the surface temperature of Mars is very low. Most of the water is preserved in the form of underground ice, and some of it is imprisoned in the permanent polar cap. The extremely thin atmosphere makes ice sublimate directly into water vapor when the temperature is high enough. Free-flowing water seems impossible. Some people think that in the early history of Mars, frequent volcanic activities discharged a large number of volcanic gases such as ammonia and methane, and this thick primitive atmosphere would have a strong greenhouse effect, thus warming the surface of Mars and creating conditions for the flow of water in rivers. Later, volcanic activity decreased, volcanic gas gradually decomposed, light element atoms escaped to interstellar space, and heavy element atoms combined with other components, making the atmosphere of Mars thin, dry and cold, and the surface of Mars became what it is now. Some people think that in the early history of Mars, the inclination of the rotation axis was larger than it is now, so the polar caps of the two poles melted, a large amount of carbon dioxide entered the atmosphere, and a large amount of water evaporated and condensed into raindrops and landed in the equatorial region, forming rivers. As for some large river beds, it is estimated that volcanic activity and geothermal energy melted the ice underground, and a large amount of water washed the surface of Mars. In addition, there are many gullies obviously washed by water, which seems to prove that there was water on Mars at least before.

Mars is the fourth and seventh largest planet in the solar system.

Orbit: 227,940,000 kilometers (65,438+0.52 astronomical units) from the sun.

Planet diameter: 6794 km

Quality: 6.42 19e23

Mars (Greek: God of War) is called God of War. This may be due to its bright red color; Mars is sometimes called the "red planet". (Interesting note: Before the Greeks, the ancient Romans once offered sacrifices to Martians, who were a god who seldom talked about agriculture. On the other hand, aggressive Greeks regard Mars as a symbol of war, and the name of March also comes from Mars.

Humans have known about Mars since prehistoric times. Because it is considered to be the best place for human beings to live in the solar system (except the earth), it is loved by science fiction writers. Unfortunately, the famous "Canal" and other things Lowell "saw" are just as fictional as Princess Barsoumian.

The first exploration of Mars was carried out by Mariner 4 in 1965. Several attempts have been made, including two Viking planes (left) in 1976. Then, after a lapse of 20 years,1July 4, 997, the Mars Pathfinder finally landed on Mars successfully (right).

The orbit of Mars is very elliptical. Therefore, where the sun shines, the temperature difference between perihelion and aphelion is close to 30 degrees Celsius. This has a great influence on the climate of Mars. The average temperature on Mars is about 2 18K(-55℃, -67F), but its span ranges from 140k(- 133℃, -207F) in winter to nearly 300k(27℃, 80F) in summer. Although Mars is much smaller than the earth, its surface area is equivalent to the land area of the earth's surface.

Besides the earth, Mars is a solid surface planet with the most interesting terrain. There are some spectacular terrains here:

-Mount Olympus: It is 24 kilometers (78,000 feet) above the earth's surface and is the largest mountain range in the solar system. Its bottom is more than 500 kilometers in diameter and is surrounded by cliffs as high as 6 kilometers (20,000 feet) (right);

-Tarsis: a huge bulge on the surface of Mars, about 4,000 kilometers wide and 10 kilometers high;

-Mariner's Valley: a canyon group with a depth of 2 to 7 kilometers and a length of 4,000 kilometers (the title is as follows);

-Hellas Planitia: an impact crater with a depth of over 6,000 meters and a diameter of 2,000 kilometers in the southern hemisphere.

There are many ancient craters on the surface of Mars. But there are also many newly formed valleys, ridges, hills and plains.

In the southern hemisphere of Mars, there is a curved circular highland (left) similar to that on the moon. On the contrary, most of its northern hemisphere consists of newly formed low-level plains. The formation process of these plains is very complicated. There is a huge height change of several kilometers on the north-south border. The reason for the great difference between the north and the south and the high upheaval in the border areas is still unknown (some people speculate that this is due to the huge force generated by the increase of alien objects on Mars). Recently, some scientists began to wonder whether those steep mountains were in their original places. This question will be answered by the Mars Global Explorer.

The internal situation of Mars can only be inferred from its surface information and a large number of related data. It is generally believed that its core is composed of high-density substances with a radius of 1700 km; Wrapped in a layer of lava, thicker than the earth's mantle; The outermost layer is a thin shell. Compared with other solid planets, the density of Mars is lower, which indicates that the iron (magnesium and iron sulfide) in the core of Mars may contain more sulfur.

Like Mercury and the Moon, Mars lacks active plate movements; There is no indication that there has been crustal translation on Mars, which can cause as many folded mountains as the Earth. Because there is no lateral movement, the giant hot zone under the crust is at rest relative to the ground. Coupled with the slight gravity on the ground, it led to the Taris bulge and huge volcano. However, people have not found any signs of volcanic activity recently. Although there may have been many volcanic movements on Mars, it seems that there has never been any plate movement.

There have been floods on Mars and some small rivers on the ground (right), which clearly proves that many places have been eroded. In the past, there was clean water on the surface of Mars, and there might even be great lakes and oceans. But these things seem to have only existed for a short time, estimated to be about 4 billion years ago. (barres Maneris is not made of running water. It is caused by the extension and impact of shells, accompanied by Tarsis uplift).

In the early days of Mars, it was very similar to the Earth. Like the earth, almost all the carbon dioxide on Mars is converted into carbonaceous rocks. However, due to the lack of plate movement of the earth, Mars can't recycle carbon dioxide into its atmosphere again, so it can't produce significant greenhouse effect. Therefore, even if it is pulled to the same solar distance as the Earth, the surface temperature of Mars is still much colder than that of the Earth.

The thin atmosphere of Mars is mainly composed of carbon dioxide (95.3%), nitrogen (2.7%), argon (1.6%), and trace oxygen (0. 15%) and water vapor (0.03%). The average atmospheric pressure on the surface of Mars is only about 7 mbar (less than 65,438+0% on Earth), but it varies with height, reaching 9 mbar in the deepest part of the basin and only 65,438+0 mbar at the top of Mount Olympus. But it is also enough to support hurricanes and big storms that occasionally sweep the whole earth for a month. Although the thin atmosphere of Mars will also have a greenhouse effect, it can only raise its surface temperature by 5K, which is far lower than the temperature of Venus and the Earth as we know it.

The poles of Mars are permanently covered with solid carbon dioxide (dry ice). The structure of this ice sheet is layered, which is formed by the alternating overlapping of ice layers and the change of carbon dioxide layers. In the summer in the north, carbon dioxide is completely sublimated, leaving the remaining ice water layer. Since the carbon dioxide in the south has never completely disappeared, we can't know whether there is ice under the ice in the south (left). The reason for this phenomenon is not clear, but it may be climate change caused by the long-term change of the angle between the equatorial plane of Mars and its orbit. Maybe there is water deeper under the surface of Mars. This change in polar cover caused by seasonal changes has changed the pressure on Mars by about 25% (measured by Viking).

However, recent observations through the Hubble telescope show that the Viking survey environment was not typical at that time. Now the atmosphere of Mars seems to be colder and drier than that detected by Viking (see STScI website for details).

Viking tried to do an experiment to determine whether there is life on Mars, but the result was negative. But optimists point out that only two samples are qualified, and they are not from the best place. Future Mars probes will continue to conduct more experiments.

A small meteorite (SNC meteorite) is thought to come from Mars.

1On August 6th, 996, David Mackay and others claimed that the composition of organic matter was found in Martian meteorites for the first time. The author even said that this composition, together with some other minerals obtained from meteorites, can be a proof of the existence of ancient microorganisms on Mars. (left? )

Such an amazing conclusion does not lead to the conclusion that aliens exist. Since David Zhu put forward his viewpoint, some opponents' studies have also been published. But any conclusion should be "reasonable and well-founded". There are many things to be done before the conclusion is announced with complete certainty.

There is a large area of weak gravity in the tropical region of Mars. This is an unexpected discovery when the global Mars probe entered the orbit of Mars. They may have been left behind when early shells disappeared. This may be very useful for studying the internal structure of Mars, past atmospheric pressure and even the possibility of ancient life.

Mars is easy to see with the naked eye in the night sky. Because it is close to the earth, it looks very bright. Mike Harvey's planet search map shows the positions of Mars and other planets in the sky. More and more details and better charts will be discovered and completed by astronomical programs such as "Starlight".