halley's comet

wikipedia.org

The Halley Comet (officially named 1P / Halley) is better known as a short-duration comet. It is visible from the earth every 45 to 6 years. Heli is the only short-term comet that can be seen clearly with the naked eye from the Earth and is the only comet seen with the naked eye that appears twice in human life. Other comets appearing with the naked eye may be brighter and more visible but they appear only once in thousands of years.

Halley returned to the inner solar system by its astronomers in 240 CE. Observations and records have been recorded since. Clear records of the appearance of this comet were recorded by the Chinese, Babylonian, and medieval European rulers, but at that time it was not recognized as a recurring comet. It was first identified as a recurring comet by the British astronomer Edmund Halley in 1805 and was later named Halley Comet after him. The Halley comet last appeared in the inner solar system in 1949, and it would next appear in the middle of 2061.

Halley became the first comet during its entry in 1949 which was studied closely and in detail by the spacecraft. It provided the earliest observational data on the structure of Heli's navel and the mechanism of coma and tail formation. This observation provided the basis for long-standing concepts about the comet's structure, particularly Fred Whipple's 'Dirty Snow Ball' model. He correctly estimated the structure of Halley as being composed of a mixture of volatile substances such as water, carbon dioxide, ammonia, and dust. The data provided by this mission has greatly improved our thoughts about Heli. For example, we now understand that the surface of the Halley Comet is largely made up of dust and non-volatile materials and only a small part of it is made up of ice or volatile matter.

Class calculation

Halley is the first comet that was recognized as a recurring comet. Aristotle's belief in the nature of comets was the consensus among the then philosophers that comets were the result of disturbances in the Earth's atmosphere. This idea of ​​Aristotle was proved wrong in 1557 by Tycho Brahe. Tycho used parallax measurements to show that comets exist beyond the moon. Many people still disagreed that comets actually orbited the Sun and believed that Comet followed a straight path and passed through the solar system.

In the year 18, Sir Isaac Newton published his Principia, in which he outlined his laws of gravity and motion. His work on the comet was certainly incomplete, although he suspected that the Comet, which first appeared in the years 170 and 171 and appeared after passing through the Sun, was the same. His belief was later found to be correct. He was completely unable to reconcile the comets in his model. Finally, Newton's friend, editor, and publisher Edmund Haley, in his Synopsis of the Astronomy of Comets in 1805, used Newton's new laws to calculate the gravitational effects of Jupiter and Saturn on comet orbits. This calculation enabled him to examine historical records and determine orbital elements. He found that the second Comet, which appeared in 1772, is almost the same as the two Comet which appeared before today in 1531 (observed by Petrus Appianus) and in 1806 (observed by Johannes Kepler). In this way Hailey concluded that the three Comet is, in fact, the same, returning every 4 years. This period was later revised to 75–7 years. Considering the gravitational effects of planets falling on comets, it was predicted after a rough estimate that Halley would return in 1858.

The Halley Comet return prediction proved to be correct. It was spotted on 25 December 1857 by a German farmer and amateur astronomer Johann Georg Pelsijk. Hailey himself could not see the return of this comet in his life as he died in 1872. Confirmation of this Comet return showed for the first time that bodies other than planets exist which revolve around the Sun. This comeback was a successful test of pre-Newtonian physics as well as a clear demonstration of its explanatory power. This Comet was named in 1859 by the French astronomer Nicolas Louis de LaSalle in honor of Hailey.