2021-09-27

Scientists found that the “two brothers” of earth and Venus grew up in collision

By yqqlm yqqlm

Scientists found that the “two brothers” of earth and Venus grew up in collision < / P > < p > these findings challenge the traditional view. The traditional view is that the collision between smaller celestial bodies will cause them to stick together, collide continuously over time, absorb new material and form a growing small planet</ p> < p > on the contrary, the two authors proposed and proved a new “collision escape return” scenario. In this scenario, celestial bodies before the formation of planets collide and rebound with each other during most of their journey through the interior of the solar system. They slow down on the first collision and are more likely to stick together on the next collision. Like a billiards game, the ball gradually stops</ p> < p > two papers published in the Journal of planetary science on September 23, one focuses on Venus and the earth, and the other on the moon. According to Erik asphaug, Professor of planetary science at the University, the core of the two papers focuses on a largely unrecognized view that a single celestial impact will not form what scientists believe to be an effective merger</ p> < p > “we found that most celestial body impacts, even relatively ‘slow’ impacts, run away after collision. This means that if two planets want to merge, they usually have to slow down during the escape after collision.” it may be wrong to regard the impact, such as the formation of the moon, as a single event. It is more likely to be two consecutive collisions. ” < / P > < p > one implication is that although Venus and the earth are close neighbors within the solar system, their growth processes have very different experiences. This study found that the young earth will slow down the speed of planets, eventually making them more likely to collide with Venus and adhere to the golden star. “We believe that the early Earth acted as the vanguard of Venus during the formation of the solar system.” Said Alexandre emsenhuber of Ludwig Maximilian Munich University, the first and corresponding author of the paper. < / P > < p > < img SRC = ‘ https://n.sinaimg.cn/tech/transform/27/w529h298/20210927/7e37-31433e71def8c3ace7cbc4aa262787ef.jpg ‘/ > < / P > < p > the solar system is what scientists call a “gravity well” , tourists throw coins into a funnel-shaped gravity well, and then watch the coins orbit several times and fall into the center of the gravity well. The closer the planet is to the sun, the stronger its gravity is. That’s why the planets Mercury, Venus, earth and Mars in the solar system concerned in the study orbit the sun faster than Jupiter, Saturn and Neptune. Therefore, the closer an object is to the sun , the more likely it is to stay there. < / P > < p > alpha UG explained that when a planet that broke into the earth hits the earth, it is less likely to adhere to the earth, but is more likely to eventually fall on Venus. “The earth is like a shield, providing the first stop against the impact of these planets,” he said, “It is more likely that a planet bouncing back from the earth will collide with Venus and merge with it.” < / P > < p > emsenhuber uses the analogy of a ball jumping down a staircase to illustrate the “pioneer effect”: a celestial body outside the solar system is like a ball jumping down a set of stairs, and each rebound represents a collision with another object. < / P > < p > “In this process, the ball loses energy, and you will find that it can only bounce down, not up,” he said. “Therefore, this celestial body can no longer leave the interior of the solar system. Similarly, you usually only go downstairs towards Venus, and the day that collides with Venus will stop in the interior of the solar system, and it will hit Venus again at some time.” < / P > < p > the earth does not have such a vanguard to slow down the speed of planets. The author believes that this leads to the difference between two planets of similar size that cannot be explained by traditional theories. < / P > < p > “the general view is that if the planets collide but do not merge immediately, it is not important because they will collide again at a certain point and then merge,” essenhuber said, “But that’s not what we found. We found that they will become part of Venus more often than return to earth. It’s much easier to get from earth to Venus than vice versa.” < / P > < p > in order to track the orbits and collisions of these planets and eventually their merger, the team used machine learning to obtain prediction models from the 3D simulation of celestial collision. The team then used these data to quickly calculate the orbital evolution, including post collision escape and merger collision, and simulate the formation process of earth like planets for 100 million years. < / P > < p > in the second paper, the author proposed And demonstrated their “impact escape return” The main problems of the standard celestial impact model are recognized. < / P > < p > < img SRC = ‘ https://n.sinaimg.cn/tech/transform/82/w529h353/20210927/cbe2-c1ab86047f9be6822edca184c84a5a2e.jpg ‘/ > < / P > < p > the moon is considered to be the consequence of a huge impact. According to the new theory, it has had two consecutive huge impacts, including fire, at an interval of about 1 million years The impact between the star sized planet Theia and the original earth. In the figure, the author simulated the collision scene of “hit and run” in 3D. The section shows the internal iron core. Theia (or most of it) hardly escaped, so it is likely to have a subsequent collision. A. emsenhuber / University of Bern / University of Munich < / P > < p > “Relatively speaking, the standard model of the moon requires very slow collisions,” said asphaug. “The moon it creates is mainly composed of impact planets, not the original earth, which is a major problem because the isotopic chemical composition of the moon is almost the same as that of the earth.” < / P > < p > the team envisages that a protoplanet about the size of Mars will hit the earth, just like in the standard model, but slightly faster, so it will continue to move forward. It will return to a huge impact that looks much like the standard model in about 1 million years. “Two collisions are much more mixed than one, which can explain the isotopic similarity between the earth and the moon, and how the second slow merging collision occurred.” The researchers believe that the resulting asymmetry in planetary assemblages points the way for future research on the diversity of earth like planets. For example, why does the earth have a much stronger magnetic field than Venus and why Venus has no satellites. < / P > < p > “In our opinion, most of the earth’s material is accreted due to frontal collision, or slower than Venus,” he said. “More inclined and faster collisions will take priority on Venus.” < / P > < p > this will produce a deviation. For example, protoplanets from the outer solar system will preferentially accrete to Venus rather than the earth at higher speeds. In short, Venus may be composed of materials that are more difficult for the earth to obtain. “You might think that the earth is made up of more extrasolar material because it is closer to the extrasolar system than Venus. But in fact, with the pioneering role of the earth, Venus is actually more likely to absorb extrasolar material,” said asphaug