The origin of bad luck?
When introducing the modern solar system theory of western science in the book Introduction to Astronomy, the book wrote: "Astronomy has a long history, but the ancients all called it a round place." This "ancients" should include China people, and "the sky is round and the place is round" is obviously the traditional concept of China.
When introducing comets, the book wrote: "Comets are weird stars with a head and a tail, so they are called broom stars because of their shapes." At the same time, words similar to "broom star" include "broom guy", "broom eyebrow" and "broom head"
Physical characteristics:
Except when the comet is far away from the sun, its long, bright and sparse tail in the past gave people the impression that the comet is close to the earth, even in our atmosphere. 1577 tycho pointed out that comets do not show different orientations from different places on the earth: therefore, he correctly concluded that they must be far away.
Whenever a comet approaches the sun, its brightness will increase rapidly. Observations of comets that are quite far from the sun show that they move along a highly elongated ellipse, and the sun is located at a focus of this ellipse, which is consistent with Kepler's first law. Comets spend most of their time away from the sun, where they are invisible.
Reference to the above content: Baidu Encyclopedia-Comet