It is said that Mars and the Earth are twin brothers. What do they have in common?

The fiery red Mars is not only the yearning of many people, but also the yearning of science. Over the years, dozens of probes and rovers have gone to Mars. Mars is so desolate, is there anything to investigate? In fact, the reason why scientists want to investigate Mars is because Mars is a rocky planet like the Earth, and it is easier to investigate than Mercury and Venus. In addition, Mars also has a history of geological activity.

This is the scientific analogy method, seeing the Earth from Mars, and studying the origin of the whole solar system. Mars and Earth are both rocky planets. What are their similarities? Such as climate, geological conditions, whether there are traces of primitive life, whether there is water, and whether there is an atmosphere similar to the earth, this is the significance of investigating Mars.

These are three Mars rovers, representing different rover structures in three eras, with two engineers as reference.

Over the years, every mars orbiter mission or Mars probe has its own goals, such as the Perseverance Mars probe launched in July this year, whose goal is to study the traces of ancient life, and the Curiosity Mars probe is to study the surface topography of Mars and find traces of ancient Martian water. Planets are not only landforms, but also history, and there are more investigation references. Only by combining these reference factors can we understand the real Mars.

human probes can be said to be all over the solar system. From asteroids to major planets, the most fascinating thing is what their surfaces look like and their internal structures.

There is a trend in modern human space exploration, that is, the farther away from the earth, the farther away your dreams are ... the first time you reach orbit, the first time you reach near-earth orbit, the first time you walk in space, the first time you land on the moon, and so on. There is no doubt that we will land on Mars in the future. No matter at that stage of space exploration, we need to explore comprehensively and understand all the contents of the new stage. Landing on Mars? We need to know more about Mars, just as we knew about the moon in the past. Next, we will take the Insight express to learn about Mars together.

The Mars probe Insight was launched on the Atlas 5 41 rocket, and Insight successfully landed on Mars. Insight Mars probe is the first probe focusing on the internal situation of Mars. To understand a planet, we also need to look at the structure of the whole planet. So why do we say that Insight can gain insight into the interior of Mars? Mainly because of its scientific load.

Atlas V fairing, Insight Mars probe has been integrated in the fairing and photographed in the preparation stage before launch.

Insight Mars probe carries a seismograph called SEIS, which can measure earthquakes inside Mars and draw the structure map of Mars underground. Seismographs alone are not enough. Insight Mars probe also carries a thermal probe structure named HP, which can go more than 5 meters underground to explore the changes of heat flow and underground structure in the early stage of Mars. In addition, Insight also has a planetary rotation and magnetic field structure tester RISE. Through the combination of X-band rays of the lander itself and RISE, Insight can better understand the internal magnetic field and rotation axis of Mars. Knowing the swing amplitude of the rotating shaft, the global magnetic field and other parameters, scientists can infer all the structural information inside Mars.

According to these three items, you can see that they are all aimed at the interior of Mars, and the three scientific loads study Mars from the aspects of Mars geology, Mars geological evolution and Mars global magnetic field. Next, let's talk about Mars from these three aspects, which is the most similar planet in the solar system to the Earth.

The evolutionary history of Mars probe is like the process of exploring science, step by step, more complete, step by step, more powerful, until the astronauts landed on Mars, but before that, we still need to further investigate the geological structure of Mars.

The most critical step for a Mars lander is to choose a landing site, especially for a Mars probe like Insight, which will not move. The landing site seems to be its own. Insight landed in the western part of Mars' Elucian Plain at an altitude of -2.613 km, which is a volcanic plain with a surface age ranging from 3.7 billion to 2.5 million years. There are many traces of faults, volcanic flows and liquid water flows around Insight, and there are many impact craters of different sizes around it. The lander of Insight is located in a crater with a diameter of about 25 meters, which is full of sediments produced by impact. These sediments have been eroded by the wind for millions of years and have obvious wind erosion.

From the shallow to the deep, we can look at the surface of Mars first. On the second day after the successful landing, Insight started the mode of scientific load multi-cooperation, and described the near-surface characteristics of Mars for us. On the second day, the joint investigation data of HP and seismograph recorded an earthquake caused by atmospheric vortex. Through the underground signal of Mars, Insight found a near-surface layer of Mars with high porosity and low stiffness about 3 meters thick. Finally, the thermal inertia data near the surface of Mars are measured by infrared radiometer, which is consistent with the situation of the sandy surface of the earth through comparison.

The Mars probe Insight landed in the west of the Elucian Plain. The landing positions of Curiosity, Spirit and Pirate 2 are all shown on this topographic map.

Mars will also quake.

Insight recorded 174 earthquake events, 15 of which were very small in magnitude, with the perceived energy only above 1 Hz. Scientists are still analyzing the earthquake source and distance. However, the other 24 earthquake events are mainly low-frequency, and their spectral shapes have the same scale law as lunar earthquakes (lunar earthquakes). Therefore, scientists have determined that these 24 earthquakes are caused by the Martian structure, and the others are surface vibrations caused by asteroid impacts or weather problems.

This frequency chart shows us the Mars earthquake detected by Insight. There are many types of earthquakes on Mars, such as the falling of distant asteroids and the noise of the Martian wind. Sometimes the frequency generated by the movement of the robotic arm of Insight will be recorded. This earthquake data is analyzed because of the Martian wind.

According to the data brought by Insight, scientists predicted the global earthquake event rate of Mars. The results show that this planet is moderately active, and Mars has its own geological activities, and its value is much higher than that of the moon (this summary does not include the deep moon earthquake related to the tidal stress of the moon). Undoubtedly, the seismograph results of Insight reveal the internal structure of Mars and the active frequency of earthquakes on Mars. These observations can give scientists a new understanding of the internal structure and geological evolution of Mars.

The concentration of light elements in the core of Mars is twice that of the Earth, and the core of Mars may be made of iron, nickel and sulfur, and some of it is in a fluid state. On Mars, the mantle and crust are made of rocks rich in silica. In addition, the crust of Mars is much thicker than the earth, with a depth of 5-125 kilometers. In contrast, the average level of the earth is 4 kilometers.

Climate of Mars

There are many criteria to measure a planet, such as the geological problems of Mars, the internal structure of Mars and the key problem of Mars. We know that Mars has no global magnetic field, so it is impossible for Mars to have such a dense atmosphere as the Earth, and it is impossible for it to rain and snow ... But it is strange that it will be windy, there will be global storms, clouds and so on. In the future, the Martian climate problem will become more and more important, because the Martian climate problem will directly affect the safety of the Martian astronauts.

Now scientists have an opportunity to expand our knowledge of the atmosphere beyond the earth's atmosphere. Although Mars has an atmosphere, its atmosphere is very thin, and fine dust and aerosols cover its dry and desolate surface. Here, we see the atmosphere on another planet. Insight detector has IDC color camera and TWINS climate observer. TWINS can observe the temperature, humidity, ultraviolet intensity, wind level and other weather and climate problems of Mars. TWINS has unique sensitivity to regional weather, while IDC camera can directly image the distant weather.

how to explain the early wetness of Mars? One possibility is caused by large impact events, which triggered major climate changes. Scientists have made many simulations, and the data show that the impact will produce a lot of rainfall in a relatively short time. < P > Insight has provided many key data for scientists to study the atmospheric state of Mars through more than one year of continuous data recording. Through the investigation data, scientists found that all these weather phenomena, from thermal tides and baroclinic instability to regional gradient winds and gravity waves, are stronger and more severe than those on the earth. In other words, the weather on Mars is much worse ...

This is the Arctic ice sheet of Mars, which will help scientists to understand some conditions in the early ice age on Mars in the future

Besides, Insight also made an unexpected discovery-Mars also has some atmospheric features that the earth does not have, such as the main atmospheric component of Mars is carbon dioxide, which will condense in the polar and equatorial sky of Mars. The investigation is still going on, and scientists still can't explain some problems, such as how Martian dust rises from the surface and how to use Mars as a laboratory to explore some special meteorological phenomena on earth. In order to solve these problems, it is not enough to rely solely on Insight, but also need the joint observation of multiple detectors and satellites in orbit. Only by integrating the data of these detectors or satellites in orbit can we truly understand the climate of Mars.