About Mars, its formation time, geographical environment, surrounding location, exploration process, legend! !

Mars is one of the eight planets, ranking fourth in the sun from near to far. To the naked eye, Mars is a striking lux star, moving slowly among the stars. On the earth, it moves forward and backward, 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 myth of Mars, the god of war, dressed in armor and covered in blood. In Greek mythology, Mars is also regarded as the god of war. 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, the solar radiation energy it receives is only 43% of that 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℃. 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 of 24 hours, 37 minutes and 22.6 seconds. A day and night on Mars is slightly 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. 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 Driss. Mars is a close neighbor of the earth. It shares many characteristics with the earth. They all have satellites, moving sand dunes, sandstorms raised by strong winds, and white ice caps at the north and south poles, except that the ice caps on Mars are dry ice. Mars rotates once every 24 hours and 37 minutes, with an axis inclination of 25 degrees, which is almost the same as that of the Earth. 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 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. (USGS) internal structure diagram of Mars. The internal structure of Mars is similar to that of the Earth, with a shell, a mantle and a core. However, due to incomplete data, the composition and size of the core of Mars are still uncertain. The landscape on the surface of Mars. This was taken by a probe that landed on the surface of Mars. In the distance, you can see the peak of Mars called "Shuangfeng". (NASA) Rivers crisscross the surface of Mars. These riverbeds have dried up, but they may have been formed by massive floods in ancient times. A large-scale sandstorm rising on the surface of Mars. Sandstorm occurred near the South Pole of Mars, and its influence range was about several hundred kilometers. This is the flaky landform in the Antarctic region of Mars photographed by NASA's Viking 2 probe. These stripes are composed of ice and sediments. Mars is called the red planet, because its surface is covered with oxides, so it appears rust red. The surface of Mars is mostly desert, with a lot of red oxides, ochre gravels and solidified lava flows. There are often violent winds on Mars, which can raise dust and form a super-large sandstorm that can cover the whole planet of Mars. Every sandstorm lasts for weeks. Both the ice sheets at the poles of Mars and the atmosphere of Mars contain water. The detection data obtained from the surface of Mars prove that in ancient times, Mars once had liquid water, 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 that there are 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. There is a huge "sailor's valley" on the surface of Mars. This is a huge canyon about 4000 kilometers long, which was formed under the joint action of floods and volcanic activities in ancient times. Mount Olympus, a huge volcano on Mars, is about 27,000 kilometers high, which is three times the height of Mount Everest, the highest peak on the earth. It is the highest mountain in the solar system. Mars has two tiny satellites, both less than 80 kilometers in diameter, which look more like captured asteroids. Because Mars is similar to Earth, it has always been considered that there is the possibility of extraterrestrial life. Recent scientific research shows that there is no proof of 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. Mass 6.421e+23kg equatorial radius 3,397.2km average density 3.94g/cm3 average daily distance 227,940, 000 km rotation period 24.6229 hours period of revolution 686.98 days equatorial surface gravity 3.72 m/s 2 equatorial escape velocity 5.02 km/s minimum surface temperature-140℃ average surface temperature -63℃ maximum surface temperature 20℃ atmospheric pressure 0.007 bar 00029 1%190. That flight found no evidence of life on Mars. However, Schoultze Macuch, an American geologist, published a paper saying that the probe might have really discovered Martian creatures at that time, but people didn't realize their existence at all, because the form of Martian creatures was so different from 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.