Why hasn't the "mother of meteor showers" been seen for a hundred years?, Perseid meteor shower, annual meteor shower
As an anticipated blockbuster in August, the Perseid meteor shower will make a stunning debut on the 13th, ushering in its peak season. The observant public will notice that the Perseid meteor shower visits Earth at a relatively fixed time every year, but its parent comet Swift Tatel takes over 130 years to approach Earth once. Why do meteor showers occur every year, but the "mother of meteor showers" is rare to see in a hundred years? Astronomical science popularization experts reveal secrets for you.
Wang Kechao, director of science popularization at the Purple Mountain Observatory of the Chinese Academy of Sciences, said that to explain this problem, the first thing to do is to talk about the cause of the meteor shower. The parent material of meteor showers is mostly comets. The dust left by a comet in its orbit around the sun enters the Earth's atmosphere, emitting light and forming a meteor. When meteors swarm through the atmosphere, people on Earth can see meteor showers.
Every time Comet Swift Tatel approaches the Sun, it is called a return, and this period is basically consistent with the period it approaches the Earth. On its orbit around the sun, the comet continuously spews out dust, spreading throughout its entire orbit. Although the Earth may not encounter this comet every year, it will pass through its orbit on similar dates and meet the dust in its orbit every year. Specifically, in the Perseid meteor shower, from mid July to late August each year, the Earth passes through the "dust belt" of the orbit of Comet Swift Tuttle, which is why the "mother of meteor showers" is not common, but meteor showers occur every year.
Whenever the parent comet of a meteor shower returns, the "rainfall" of the meteor shower will erupt, because the parent comet releases a new batch of dust when it returns. For example, in 1992, with the return of Comet Swift Tuttle, the Perseid meteor shower experienced a "major eruption", and the number of meteors doubled compared to usual. The famous Leonid meteor shower, whose parent comet returns every 33 years or so. In the years before and after the return, the Leonid meteor shower may also experience a "major eruption".
