The secret to spending 100 million years successfully “sliming down” small ceres “the ends of the earth” is to bask in the sun.

Hundreds of millions of small ice-containing objects in the Kerber Belt are thought to be primitive stars left over from the early formation of the solar system and the source of half-human horse bodies and Jupiter comets. Therefore, the study of the Kerber Belt objects is of critical scientific significance to understanding the origin and evolution of the solar system, the origin of water and life on Earth. On New Year’s Day 2019, NASA’s New Horizons probe flew over the 2014 MU69, a small object in the Kerber Belt.

这是目前人类探测到的最遥远和最原始的太阳系天体,它那扁平的双瓣状结构,宛如一个胖乎乎的雪人。这个“胖娃”引起了科学家的浓厚兴趣。它的名字Arrokoth来源于美洲原住民波瓦坦人的语言,意指“天空”;同时它也有个诗意的中文名字——“天涯海角”。

On October 5, Nature Astronomy published online the results of a joint research study with Zhao Yuxuan, Associate Researcher of the Planetary Science and Deep Space Exploration Laboratory of the Zijinshan Observatory of the Chinese Academy of Sciences, and other institutions such as the Mapu Institute of Solar Systems in Germany. Scientists built and used models of the evolution of the shape of the solar system’s small objects, analyzed the strange flat shape of the “ends of the earth” and came to a completely new conclusion: this round “fat woman” after its birth 10 Between 100,000 and 100 million years, the volatility of active gases such as methane, carbon monoxide and nitrogen led to the formation of its flat structure, and this “slimming” mechanism may have been widely present in the early shape evolution of small objects in the Kerber Belt.

Mysterious Kerber with small cerial bodies.

The Kerber Belt is named after G.P. Kerber, a Dutch-American astronomer.

In 1951, Coeber developed the irish astronomer E. Echworth’s idea of the origin of short-cycle comets into a corresponding theory, and later people referred to the expected ring as the Kerber Belt, or Echworth-Coyber Belt.

In 1992, astronomers used optical telescopes to observe an asteroid in a circular orbit outside Nep neptar’s orbit, and later discovered more similar objects. By 2006, the total number of observations had exceeded 1,000, the largest of which was 1,200 kilometers in diameter and the rest in diameter of 200-400 kilometers.

Now, humans have been able to observe countless small objects in the Kerber Belt through ground-based telescopes, or, like New Horizons, fly over the Kerber Belt to take close-ups of mysterious objects.

Zhao Yuxuan told Science and Technology Daily that the Kerber Belt is located outside the disk of the solar system, beyond Nepase’s orbit, 30-50 astronomical units from the sun (AU, 1 astronomical unit is about 149.6 million kilometers), mainly composed of small objects or remnants of the formation of the solar system.

Similar to the asteroid belt, it is home to hundreds of millions of solid-state objects and is home to Jupiter’s comets. But unlike the asteroid belt, most Kerber Belt objects are made up mainly of frozen volatiles, such as carbon dioxide and water, rather than metal.

The most famous object in the Kerber Belt is Pluto, once the ninth largest planet in the solar system. But it was later excluded, in part because it was about the same size as some of the smaller objects in the Kerber Belt.

The origin of small objects in the Kerber Belt remains an open mystery, and scientists tend to think that small objects in the Kerber Belt of different groups may have formed at different locations in the solar system. 4.5 billion years ago, in areas close to the sun, many interstellar matter circled and collided with each other, forming the solid nucleies of Earth and other Earth-like planets, as well as gas giants. In areas far from the sun, such as the Kerber Belt, temperatures are extremely low, and many cosmic dust, ice, and gas are preserved, creating a large number of objects smaller than planets.

Retains the material of the early days of the solar system.

Hundreds of millions of small ice-containing objects in the Kerber Belt are thought to be primitive stars left over from the early formation of the solar system and the source of half-human horse bodies and Jupiter comets. Therefore, the study of the Kerber Belt objects is of critical scientific significance to understanding the origin and evolution of the solar system, the origin of water and life on Earth.

As one of the most stable small objects in the Kerber Belt, the “cold classic” group, its orbit is seldom disturbed by the outside world in the course of evolution, and belongs to the region’s native ceres. The exploration of “the ends of the earth” can provide a great deal of valuable information for human beings to study the formation and evolution of the solar system and its celestial bodies.

“We call ‘the end of the earth’ the ‘cold classic’ not because of its low temperature, but because, in terms of dynamics, the orbit of such objects is more stable, arguably the most stable kind of celestial body in the solar system.” Zhao Yuxuan said that in addition to the “cold classic” group, in the Kerber Belt, there are “hot” classic Kerber belt objects, discrete disk small objects, Nepta resonance orbit small objects and other types of small objects.

“The End of the World” is an exciting astronomical discovery. About 6.6 billion kilometers from Earth, it is a two-part, two-valve structure with a surface diameter of no more than 32 kilometers, and its peculiar flat shape is considered the most surprising result of the New Horizons probe. And its color is red, the temperature is very low. “This suggests that it contains Torin, a substance formed by simple structural organic compounds such as methane and ethane that are formed by ultraviolet light and are present in cold objects far from stars. Available information indicates that its surface maximum temperature is about minus 218.15 degrees Celsius. Zhao yuxuan said.

In the Kerber Belt, the “end of the earth” is also a very stable “cold classic” group, it can be said that it has not changed much since its birth 4.5 billion years ago, so “the end of the earth” is likely to retain some of the early formation of the solar system material.

Radiation differences determine the “body shape” of small objects

Small objects with double-valve structures are more common in the solar system. However, flat structure of the object is relatively rare, there is no relevant theory and model for its existence to give a reasonable explanation.

Previously, the international astronomical community did not give a corresponding explanation for the strange shape of the “end of the earth”, which had been speculated to have formed during the collapse of the nebula in the early solar system.

Zhao’s team independently developed a model of the evolution of small object shapes under the volatile action of active matter, using this model to conduct research on Jupiter’s comet 67P/CG, as well as other Jupiter’s comets.

“Although our samples are limited by observational data, the model has been validated in studies such as north-south asymmetry of comet 67P/CG and surface geomorphological evolution of comets, which suggests that our model is credible.” Zhao said.

Zhao Yuxuan told reporters that although, like its name, “the end of the earth” is very far away from us, “New Horizons” for it is only a quick glance, but the study of its shape is still important.

Studies have shown that in the early stages of planetary formation in the solar system, micron-sized dust binds to each other to form millimeters or centimeter-sized particles that continue to gather to form spherical or spheroidal stars tens to hundreds of kilometers in size. The “ends of the earth” may have originally been formed by a combination of two such stars.

In the early days of the solar system, interstellar space was still filled with large amounts of gas and dust, blocking most of the solar radiation, and temperatures in the remote Kerber Belt region were still very low, with highly active molecules such as methane, carbon monoxide and nitrogen able to exist in stars in solid form. As the gases and dust in the solar system are dispersed, solar radiation becomes intense, temperatures rise, and active gases on and inside the “ends of the earth” begin to evaporate and material is gradually lost.

Because the solar radiation at the “ends of the earth” poles is much larger than the equatorial region, the rate of gas volatilization is also greatly increased, and the overall shape tends to be flat.

“This shape evolution process was completed in about 1 million to 100 million years after it was formed, a very short process compared to its age of 4.5 billion years.” Zhao said.

According to Zhao Yuxuan, in the early days of the solar system, this shape evolution mechanism is likely to be common in small objects in the Kerber Belt. But some small objects that run closer to the sun, such as half-human bodies or Jupiter comets, experience similar shape evolutions again as they are subjected to stronger solar radiation, causing relatively weakly active gases (such as carbon dioxide and water) to evaporate.

“Studies have shown that large amounts of active gases such as methane, carbon monoxide and nitrogen existed in the early days of the solar system. Understanding their mechanism of function is of great significance for studying the formation of early stars in the solar system and the formation and evolution of small objects in the solar system. Zhao yuxuan said.