What is a comet? Detailed answer

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What is a comet? Detailed answer

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What is a comet?

There was a time when the appearance of comets terrified people. They considered comets a diabolical omen, a harbinger of plague, war, death.

Today we know what comets are, but much about them remains unclear. When we first spot a comet, we see only a small bright object, although the comet itself can be several thousand kilometers in diameter.

The source of light is the "head" or nucleus of the comet. Scientists believe that it may consist of a clot of solid particles and gases. It remains a mystery to us where they came from.

As the comet approaches the Sun, a tail appears. It consists of very rarefied gas and tiny particles that are torn off the nucleus of a comet under the influence of the Sun. The nucleus of a comet is surrounded by its third part, called the "shell". It is a luminous cloud of solid matter that can reach a diameter of 250 km or more.

Comet tails vary in shape and size. Some are short and wide, others are long and thin. Usually their length reaches about 10 million km, and sometimes - 180 million km. Some comets don't have tails at all.

As the tail grows, the speed of the comet increases as it approaches the Sun. At this time, the comet moves head first. And then something strange happens. A comet moving away from the Sun moves its tail forward. This is due to the fact that the rays of the Sun tear off the smallest particles of matter from the nucleus of the comet, forming the tail of the comet, in the direction opposite to the Sun.

Therefore, when a comet moves away from the Sun, it moves with its tail forward. At this time, the speed of the comet decreases, and we gradually lose sight of it. Comets can disappear for many years, but most come back gradually. Comets revolve around the sun, some taking a long time to complete one complete revolution. For example, Halley's comet makes one revolution around the Sun in almost 75 years. Currently, astronomers have registered almost 1000 comets, but there may be several hundred thousand comets in our solar system that are invisible to us.

Author: Likum A.

Random interesting fact from the Great Encyclopedia:

Who robbed the pharaohs?

The answer to this question was found by the English archaeologist William Petrie, who, since 1880, has been studying the pyramids for 46 years. Exploring one of the pyramids, Petrie could not find the entrance. Having lost patience, he ordered the Arab workers to cut a tunnel. When it was ready, Petri crawled over it, only to find two looted sarcophagi there. He was very interested in the question of how the robbers entered the pyramid without leaving any traces.

First of all, he decided to explore all the corridors leading from the burial chamber and find a way out. Having overcome the stuffy corridors littered with stones, the completely exhausted Petri reached the entrance, which, contrary to custom, was located on the south side (usually it is located on the north). How did the robbers know about this?

He once again returned to the tomb in the way that the robbers were supposed to move. He met various obstacles, traps, false cameras. If he did not know the way, he would simply get lost in this endless maze. How did the thieves know that if the stairs suddenly broke off in the blind chamber, they should be looked for on the ceiling? How did they get around the stones that reached the ceiling? Petrie concluded that the robbers were well aware of the route and the dangers that lay in wait for them. But still, it should have taken them more than 5 months to go all the way and take out the treasures.

Undoubtedly, the robbers decided on such desecration of the tombs not at all on their own initiative, but following someone's order. Whose? Not hard to guess. Of course, the priests - the only keepers of the secrets of the pyramids. Only they could help the souls of the dead in the land of the dead, reading ritual prayers after the death of the pharaohs, who erected temples in their tombs. Therefore, they attached priests to them, who were paid a lot of money.

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