Introduce it; Halley's comet; Okay？

When it comes to Halley, people will not feel strange, because the outstanding comet-Halley's comet is named after him.

Harley was born in Haggerston near London on 1656. 1673, she entered Queen's College, Oxford University to study mathematics. 1676, 20-year-old Harley resolutely gave up the degree certificate he was about to get and boarded the ship of the East India Company alone. After three months of sea bumps, he arrived at St. Helena Island in the South Atlantic, established the first southern sky observatory, made astronomical observations for more than a year, and compiled the world's first highly accurate southern star map, which is known as the "Southern Valley". Harley urged Newton to write the foundation work of classical mechanics, Mathematical Principles of Natural Philosophy, and generously contributed to the publication of this masterpiece. These two items alone are enough to make Harley famous in history. But Harley's contribution to mankind goes far beyond this. He also discovered the long-term acceleration of the moon's movement, which proved that stars are not constant. Later, I chose comet, a field that was not involved before, and conducted in-depth research, creating a new field of understanding and studying comets.

Tycho proposed that a comet is a celestial body, but it is not clear what kind of celestial body it is. Astronomers generally believe that comets are "monsters" drifting among stars, and it is impossible to predict their whereabouts.

Harley seems to have a soft spot for comets. 1680, Harley saw the brightest comet in history while traveling in France. Two years later, on 1682, another big comet was seen. These two giant comets left a deep impression on him.

1695, Harley, who is already a clerk of the royal society, began to devote himself to the study of comets. He selected 24 comets from the comet records from 1337 to 1698 and calculated their orbits in one year. It is found that the orbits of these three comets in 153 1 year, 1607 and 1682 look exactly the same. Although the time of passing through perihelion varies from year to year, it may be due to the gravitational perturbation of Jupiter or Saturn. An idea flashed through his mind: these three comets may be three returns of the same comet. However, Harley did not come to this conclusion immediately, but painstakingly searched forward and found that there were records of big comets from 1456, 1378, 130 1, 1245 to 1066 in history.

Harley published the theory of comet astronomy in 1705, and announced that the great comet that caused great panic in 1682 would reappear in the sky in 1758 (later, he estimated that Jupiter might affect its motion and postponed its return date to 1759). At that time, Harley was over 50 years old and knew that he would never see this great comet again in his lifetime. So he wrote in the book: "If the comet finally reappears around 1758 according to our prediction, only future generations will not forget that this song was first discovered by an Englishman ..."

Some people laugh at Harley's nonsense, some people are skeptical about Harley's prediction, but many people believe Harley's prediction. The French mathematician Crajo made an accurate prediction before the return of the comet: due to the influence of Jupiter and Saturn, the comet will pass the perihelion one month before and after April of 1759.

At the beginning of 1758, messier of the French Observatory began to observe, hoping to be the first person to confirm the return of comets. 1759 65438+1October 2 1, and he finally found the comet. Unfortunately, the glory of observing the return of the comet for the first time does not belong to him. It turned out that a farmer astronomy enthusiast near Dresden, Germany, first arrived there on Christmas Eve of 1758 and found the returning comet.

1March 759, Halley's comet passed the perihelion in1March 4, just one month earlier than Craehot's prediction. At this point, Harley has been buried underground for more than ten years. The life of scientists is limited, but their contribution to science will be eternal. As Halley wished, everyone did not forget Halley and named this comet Halley's Comet.

The observation and study of Halley's comet not only confirmed the existence of periodic comets, but also greatly promoted the development of comet astronomy. In addition, Comet Halley, like a visiting ambassador, regularly reviews the planets in the solar system, experiences various environments and brings back rich information. Therefore, every time it returns, it will arouse great interest of astronomers.

Comet Halley returns once every 76 years, and most of the time it lives in the marginal area of the solar system, even with the largest telescope in modern times, it is difficult to find it. People on earth can only see it within three or four months of its return. Generally speaking, people's life span is only about 70 years old, so it is rare for a person to see Halley's comet twice. Only some "longevity stars" have this opportunity. The first time I saw it, I babbled at a young age, and the second time I saw it, I was old.

What needs to be explained to readers here is that although messier didn't become the first person to confirm the return of the comet, he didn't lose heart. Instead, he began to search for comets systematically, observing them year after year in the morning and after dusk. In his lifetime, * * * discovered 2 1 comet, and the number of comets he observed reached 46. On one occasion, King Louis XV of France joked that he was a "comet detective". Although this is a joke, it is the highest praise for messier's life-long search for comets.

Vast universe, vast space. Whenever we put the telescope into the interstellar abyss, as human beings, pride and humility always rise at the same time.

Our vast and magnificent Milky Way has 1000 billion stars, but in the infinite ocean of time and space, it is just an ordinary cosmic island.

The sun, like a dignified parent, leads its family on the banks of the Milky Way. This beautiful planet in the third orbit is our great mother-the earth.

When the ape-man walked upright, the activity of observing the stars began, and the history of astronomy was almost as long as the history of mankind itself.

Move the method of administrative division to the sky, and the sky map owned by people is as detailed as a map. Ursa major, Orion, Centauri ... So there is a zoo in the sky, which is full of fascinating myths and legends.

However, when a strange and rare astronomical phenomenon suddenly appeared, human beings once fell into extreme fear and panic, that is, the sudden arrival of comets.

In Chinese, "coma" means broom. Ordinary people always call comets broomsticks. It's really like a shiny broom hanging high in the air.

Such a furry strange celestial body suddenly broke into the orderly starry sky. No wonder people were at a loss when they were young.

The ancients once thought: "When Beidou came out, the soldiers were big; The comet is in the triad, and the monarch harms the minister. "

"Kiev Chronicle" said: "Comets indicate frequent civil strife and wicked people invading Russian land."

The book Miracle Historical Records, which is popular in Europe, said: "Comets are reliable signs of unfortunate events. The end of the world and the terrible final judgment have arrived and stood on the threshold. "

It can be said that superstitions think alike. In fact, the world is so big that there are no natural and man-made disasters in any year. It is really not difficult to pick out one or two things related to the appearance of comets. This can also be regarded as "if you want to add a crime, you can always find a solution"!

Comets certainly don't mind their grievances, but human beings have been scared for thousands of years in their own absurd stories for no reason.

Since Copernicus moved the earth away from the center of the universe, the earth has never returned to that position, so human beings have found a new starting point for understanding the universe.

The mysterious and horrible veil of comets has also been unveiled layer by layer. It turns out that it is a very common celestial body, and some people call it a tramp in the solar system.

More than 1800 comets have been discovered so far, and most of them have only met us once. After they run around the sun, they will never return along a parabola or hyperbola.

Only comets in closed orbits can go back and forth. This is a periodic comet. Scientists set 200 years as the dividing line between short-period comets and long-period comets.

Harley, a British astronomer, has studied comets almost all his life. After observing the great comet of 1682, he found that the curve it described was strikingly similar to that of 153 1 and 1607. Harley boldly concluded that this was the third appearance of the same celestial body and predicted that it would return again after 76 years.

This comet lived up to Harley's expectations. It came back on time in 1759, and Harley died in 17. With deep respect, people named this comet after its discoverer, and edmund halley's name was capitalized in the sky.

The most complete information about Halley's Comet was written by the ancestors of the Chinese nation in Chinese characters. In 6 13 BC, "in autumn and July, a star entered the Beidou". This is the first human record of Halley's comet.

From the suburbs of the solar system outside Neptune, we hurried back and forth, along a flat ellipse, until we reached the perihelion in the orbit of Venus, and then hurried around the sun. This is the path of Halley's Comet with a period of 76 years. The perturbation of a big planet often affects the accuracy of its travel schedule.

Spectral analysis shows that water, ammonia, nitrogen, methane, carbon monoxide, carbon dioxide ... and the free radicals of imperfect molecules are the main components of Halley's comet. In the cold and deep space, they are frozen into lumps with dust and gravel. Scientists vividly call comets "dirty snowballs".

Approaching the sun gradually, the surface began to be heated and vaporized, so the hibernating comet entered an active period of life. The reflected sunlight and self-laser make it put on a gorgeous coat.

The clear and dense condensate in the middle is a coma, and the hazy and fluffy gas blanket is a coma with a faint and thin hydrogen cloud at the edge, which together constitute the head of the coma.

The tail is more spectacular. Where did this big tail sweeping across the sky come from?

The fiery red sun shines on every inch of space in the jurisdiction, and at the same time throws out a steady stream of subatomic streams, forming a solar wind blowing in all directions. The fragile dust and volatiles on the comet dragged out a bright tail under the pressure of solar wind and light. No wonder the closer to the sun, the longer the tail. Wherever you go, your tail always points to the side facing away from the sun. When it bid farewell to its master and started on the road again, its tail has turned into a car light, illuminating the distance.

19 10, when Comet Halley returned for the last time, doomsday gatherings were held in many places, and people waited for the encounter between the earth and Comet Halley with irresistible terror. It was not until May 19 that the earth passed through the comet's tail unscathed that this sorrow came to an end. It turns out that the tail of a comet is a thin gas, which is more empty than the vacuum created in the laboratory. Scientists compare comets to "empty pockets" and "visible nothingness".

Halley's journey through the solar system is not a leisurely stroll. Once in the sun, it will be stripped. This material loss will lead to the extinction of Halley's comet in the distant future.

This year is the time for Halley's Comet to return. Since 19 10, the changes experienced by human society are incomparable between any two regression of Halley's comet. No one is as nervous as last time, and the whole world is looking forward to it, just like welcoming a long-awaited festival.

For the first time, the International Astronomical Society formulated the international observation plan for global cooperation of Halley's Comet, and designated 1985 to 1986 as the international observation year of Halley's Comet.

Man in the space age is no longer satisfied with waiting for him on earth. The United States, the Soviet Union, Japan and the European Space Agency all rushed to launch various detectors and fly to the sky where Comet Halley passed. This is the most grand and grand welcoming ceremony since human beings met Halley's Comet.

What gift did the return of Halley's Comet bring us? Scientists believe that comets spend most of their lives in the deep cold storage area at the edge of the solar system, just like being kept in a huge refrigerator. The materials that make up comets should be kept in the initial state at the time of formation. The study of comet, a cosmic fossil, will undoubtedly greatly enrich our astronomical knowledge and help to finally uncover the mystery of the origin of the solar system.

Yes, for most of us, there is only a precious opportunity to see Halley's Comet once in a lifetime, but human observation and exploration will be eternal. Our future generations will undoubtedly establish closer ties with Halley's Comet-when it comes back after 76 years.