With the rapid development of human astronomical technology, people know more and more about the solar system. Comets, which come and go in a hurry and have peculiar shapes, have long been a mystery of the solar system.
Just like the famous Comet Halley, which revolves around the sun with a period of about 76 years, its largest diameter is only more than 10 kilometers. Every time it approaches the sun, it will be evaporated and lose a lot of mass. We believe that in thousands of years, Halley’s comet will disappear near the sun.
Where do these comets come from? It’s a mystery.
In 1951, American astronomer Kuiper put forward such an explanation
Between 30 and 100 astronomical units from the sun, there are many frozen dust bodies around the sun.
The orbital plane of these objects is similar to that of planets, but occasionally some objects are disturbed by the gravity of exoplanets or stars and fly away from their original orbit to the sun. When they pass the orbit of inner Neptune, they are further affected by the gravity of Neptune and successfully enter the comets in the inner solar system.
The area between 30 and 100 astronomical units is the home of these comets with shorter cycle. Since then, this area has been called the Kuiper belt.
Pluto’s flat, tilted orbit also cuts into this zone. This is a perfect explanation for comets with short revolution period. Unfortunately, except Pluto, no celestial body has been observed in this imaginary Kuiper belt for a long time. Pluto seems to be the end of the sun.
Until 1992, two American astronomers who did not believe that the outer solar system was completely empty finally discovered the first Kuiper belt object, 1992 QB1.
The diameter of QB1 in 1992 is only about 200 km, the average distance from the sun is 43 astronomical units, and its revolution period is 291 years.
The discovery of QB1 in 1992 inspired the astronomers who are keen to find new planets in the solar system. The Kuiper belt has become a reality from an imaginary area and a place where telescopes gather all over the world.
From 1992 to October 2002, more than 600 Kuiper objects with diameters ranging from 50 to 1200 km have been discovered. The largest of them is the Kuiper belt object, which was discovered in 2002 and is known as quaor, but its diameter is 1250 km, which is only a little more than half of Pluto’s diameter of 2400 km.
According to the statistics of astronomers, the number of objects in the Kuiper belt with a diameter of more than 100 km, 30 to 50 astronomical units away from the sun, may reach 100000. If you add their masses together, you can make a planet that weighs one tenth of the mass of the earth. As a result, people still expect a larger Kuiper belt object to be captured by their telescopes.
Planetary scientists from MT College of California and Yale University have discovered a new Kuiper belt object, tentatively named 2004 DW. By calculation, it is about 7 billion kilometers away from the earth, with a diameter of 1400 to 1600 kilometers.
It is hundreds of kilometers more than the discovery of kuaoer at the end of 2002. Thus, it became the new champion of Kuiper belt in the history of astronomy, which was rewritten less than a month later.
NASA announced that they have discovered a larger Kuiper belt object. The new object, named Sedna, is about 2000 kilometers in diameter and may consist of ice and rock, slightly smaller than Pluto. This is the largest object found in the solar system in the 74 years since Pluto was discovered.
Sedna has a very flat and horizontal elliptical orbit, which is the most typical Kuiper belt. It takes about 10500 years to go around the sun.
The last time Sedna returned, the earth was experiencing the last ice age, and the next time Sedna returned, the face of the earth did not know what had changed. Because it is too far away from the sun, about 13 billion kilometers, Sedna’s temperature will not be higher than – 200 ℃ all year round.
In other words, the Kuiper belt is like another asteroid belt in the solar system. These small objects are made up of primitive nebulae. They are not big enough to form today’s situation.
Pluto is the most famous object in the Kuiper belt. It is well known that Pluto was reduced from the ninth largest planet to a dwarf planet.
In 2015, the Hubble telescope also discovered its satellite while observing ornithus. A small object with a diameter of only 160 kilometers. As more and more Kuiper Belt objects are discovered, astronomers begin to analyze the characteristics of these objects.
There are two types of objects in the Kuiper belt: classical and walking.
Most objects in the Kuiper belt are classical, and their outer boundaries are about 50 astronomical units away from the sun. The orbital inclination of the objects in the classical Kuiper belt is very large, with a maximum inclination of more than 30 degrees. Pluto with an inclination of 17 ° is often regarded as a classical Kuiper belt object.
However, the mass of scattered objects in the Kuiper belt only accounts for about 4%. Some scientists think that they may be too far away, so their estimation is not accurate.
Scientists now believe that the Kuiper belt ranges from 30 to 55 astronomical units. This width is about the distance from the sun to Neptune, which means that the Kuiper belt has doubled the range of the solar system.
Xiao Bian thinks that we still know very little about the Kuiper belt. However, the spacecraft new vision, which has been launched into the Kuiper belt by human beings, is studying the Kuiper belt to try to help us better understand the region. To learn more about the secrets of the solar system!
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