On July 23, NASA released the first detailed internal structure map of Mars Based on the data collected by the insight Mars probe. The results show that the internal structure of Mars is very different from that of the earth < p > NASA's insight Mars probe has been collecting Mars vibration data. Three papers published in the journal Science on Thursday used the data collected by insight to deeply analyze the geological structure of Mars, which is the first time that humans have obtained the internal structure map of other planets. The paper points out that the whole Mars is like a variety of candy, its shell is divided into two or three layers by chocolate like volcanic rocks, and the Martian mantle below has a huge hard filling like toffee. The Martian core is lighter, not like nougat at all, especially the outer core is more like a lump of syrup < p > < / P > < p > diagram: internal structure of Mars. In 1889, the earth's mantle, which is hard and dense in the upper layer and soft and high temperature in the lower layer, was first discovered. Then, the liquid outer core and solid inner core of the earth were determined in 1914 and 1935 respectively. Humans have made similar explorations of the moon. Astronauts on the Apollo mission left seismometers on the surface of the moon < p > humans are also carrying out the same exploration activities on Mars. Paula koeleeijer, a seismologist at Royal Holloway College, University of London, said that the study, using the most technologically advanced seismograph in history, represented "a major leap in planetary seismology" < p > diagram: the early research missions of the Mars probe insight only made a rough estimate of the size and properties of the internal structure of Mars. However, insight's investigation of Mars vibration makes the analysis of Mars internal structure more accurate. Scientists can use the vibration data collected by insight to simulate Mars evolution model The discovery of insight will also help scientists study other planets“ If you are a doctor who has operated on only one patient, you won't be a good doctor, "said Mark panning, a planetary seismologist at NASA's Jet Propulsion Laboratory and co-author of the paper < p > "chemical evidence shows that Mars is more like a cousin of our earth than a brother and sister. It is indeed an ancient relic of the early solar system, "said Christine Houser, a seismologist at the Institute of earth life sciences in Tokyo, Japan < p > Venus is considered to be the twin brother of the earth. Why is Mars so different from earth and Venus in geological structure? Over the past two years, insight has studied Martian magnetism, shaking around the sun and vibration waves generated by Martian vibration < p > most of the Martian tremors occur in the shallow layer. But some come from deeper places and spread repeatedly inside Mars before reaching the position of insight. The velocity and direction of the shock waves change as they travel through different materials, so scientists can use these deep vibrations to understand the internal structure of Mars < p > this is not easy. A single seismograph means that scientists can only observe one area of Mars, not the whole planet. Moreover, to build a detailed map of the internal structure of Mars, it is ideal to detect a large number of strong earthquakes across the whole planet. But the intensity of vibration on Mars has never exceeded level 4.0 < p > despite many challenges, scientists finally confirmed that the crust of the southern highlands of Mars is thicker, while that of the northern lowlands is thinner. Scientists speculated that there might have been an ocean here a long time ago. The average thickness of the Martian crust is between 24 and 72 kilometers. The crust of Mars may have three layers, the upper layer is mainly volcanic rocks broken by meteorites, and the middle layer is more coherent volcanic rocks. Scientists have not yet been able to determine the structural characteristics of the lower layer < p > like the earth, the mantle of Mars is much thicker than the crust. The upper mantle is a hard and dense rock, which is also the basis of the changing tectonic plates on the earth. In contrast, the thickness of the upper Martian mantle may be twice or even thicker than that of the upper mantle < p > this "may be a simple explanation that we can't see plate tectonics on Mars," said Amir Khan, a geophysicist at the Federal Institute of technology in Zurich, Switzerland and co-author of the paper. This rigidity may prevent the upper layer of Mars from splitting into multiple tectonic plates, so that its surface does not have such diverse geomorphic features as mountains, oceans, basins, plains, canyons and so on < p > the structure of the Martian mantle also helps scientists understand why a planet that once had volcanoes as wide as Arizona, eruptive lava flows and even covered the whole of Britain is not geologically active now < p > the volcanic and plate tectonic activities of a planet are essentially derived from the heat conduction from the planet's interior to its crust. The shock waves arriving at insight show that the Martian mantle is relatively cold, making it not easy to produce large-scale geological activities on the Martian surface < p > insight also found that the overall thickness of the Martian mantle is about half that of the mantle. Due to the lack of insulation, Mars often erupted violently when it was young, exacerbating heat loss. In addition, Mars is smaller, and it radiates a lot of heat into space at the beginning of its formation < p > the overall thickness of the Martian mantle may also help explain why Mars's protective magnetic field disappeared just 700 million years after its birth. The earth's magnetic field is powered by the circulating flow of iron and nickel in the liquid outer core. It is speculated that Mars has a similar cycle, but the rapid cooling inside it stops the flow of these materials and the magnetic field disappears < p > Mars has no magnetic field to protect itself from a large amount of solar radiation, and the Martian atmosphere is blown away like scraps of paper. The water that once frequently appeared on the surface of Mars escaped into space, turning Mars into a cold desert < p > illustration: the Mars Reconnaissance Orbiter observed signs of landslides and other geological tectonic activities on the surface of Mars < / P > < p > < insight also detected the core of Mars. The radius of Mars' core is 1800 kilometers, larger than scientists expected. Its density is not high, which is "one of the most interesting results we have found so far," Amir Khan said < p > because the earth is much larger than Mars and the density of the earth's core is quite large, all the weight presses the earth's core together. Mars, on the other hand, is very small, and its core should be slightly less compressed. However, insight found that the density of the core of Mars is only half that of the earth, which is caused by the core of the planet ?
2023-03-22 10:04:38