Chinanews client, Beijing, July 31st (Reporter Shangguanyun) "Let's watch the meteor shower together" has always been a very romantic symbol. In the early morning of the 30th, the Delta Aquarius meteor shower and the Alpha Capricorn meteor shower ushered in their maximum period at the same time, attracting many astronomers to observe. did you see it yet?

　　It doesn't matter if you miss it. The Perseid meteor shower will astound the night sky on August 12. As one of the three major meteor showers in the northern hemisphere, the Perseid meteor shower has a large and stable flow, and the zenith flow is expected to reach about 110 per hour.

How was the meteor shower named?

　　Speaking of meteor showers, the Delta Aquarius meteor shower, the Lyra meteor shower... these names always make people feel a little dazzling. In fact, the naming of meteor showers is usually related to another important concept, the radiant point of meteor showers.

On April 22, 2020 local time, the Lyra meteor shower arrived as scheduled. The picture shows the Lyra meteor shower observed in Northumberland, England.

　　"The orbits of the small debris that make up the meteor shower are almost parallel. We look on the earth as if they are emitted from a point, and this point is the radiant point." Li Geng, an associate researcher at the National Astronomical Observatory of the Chinese Academy of Sciences, told a reporter from Chinanews.com .

　　Astronomers divide the sky into several regions, these regions are constellations. When the radiant point of a meteor shower happens to be in a certain constellation, the meteor shower will be named with the name of the constellation, such as the Perseid meteor shower and the Gemini meteor shower.

　　So why do letters appear in the names of these two meteor showers in July?

　　This is because the radiant points of these two meteor showers are very close to a bright star in the sky. Take the Delta Aquarius meteor shower as an example. There are 3 meteor showers in a year whose radiant point is in Aquarius. This meteor shower is named after the closest bright star at the peak.

　　Li Geng also explained that in English, the name of the meteor shower is usually replaced with the suffix "id" or "ids" at the end of the Latin name of the constellation. For example, the English name of the meteor shower in Delta Aquarius will change from "Delta Auqarii" to " Delta Aquariids".

How did the meteor shower come?

　　When you see a meteor shower across the night sky, many people will sigh for its beauty.

Data map: In the Usut (over water) Yadan Geopark in Dachaidan, Qinghai Province, more than 200 meteors struck the night sky and staged a stunning Gemini meteor shower. (Multiple photos superimposed) Photo by Wang Junfeng

　　"For a simple analogy, there are many'small particles' in the cosmic space. When the earth moves to the corresponding position, some of them will rush into the earth's atmosphere at a very high speed, violently rubbing and glowing, which are the meteors we see. Now." Li Geng explained.

　　These "small particles" are often fragments of comets. Because comets orbit the sun, every time they approach the sun, some ice or other matter will be thrown out to stay in the orbit.

　　When the orbit of the earth intersects the orbit of the comet, these fragments rush into the atmosphere to form a meteor shower. Li Geng said, this is the reason why we see the date of a particular meteor shower every year are basically the same and very regular.

　　"Most meteoroids are very small and burned during friction in the atmosphere, so they don't pose a threat to the ground," he said.

August! Perseid meteor "can look forward to"

　　However, even if you missed the meteor shower in July, you don’t have to feel too sorry. Next, there will be the Perseid meteor shower on August 12 and the Gemini meteor shower on December 14. The annual flow of these two meteor showers is relatively stable.

Data map: Star track map and Perseid meteor under multiple exposures in Yangtiangang National Forest Park, Xinyu City, Jiangxi Province. Photo by Zhao Chunliang

　　Among them, the active period of the Perseid meteor shower is from July 17 to August 24 each year. This year, the maximum period of the Perseid meteor shower is expected to begin at 21 o'clock on August 12.

　　"The three major meteor showers in the northern hemisphere are the Quadrantids, Perseids, and Geminis. When these showers are extremely large, they usually look more obvious." Li Geng said.

　　Generally speaking, people use ZHR (Meteor Shower Zenith Hourly Occurrence Rate) to represent the size of a meteor shower, which is how many meteors can be seen in an hour under ideal conditions. For example, the Perseid meteor shower ZHR in August can reach around 110.

　　"It is not difficult to observe a meteor shower, and no special equipment is needed. Just find a relatively dark and flat place, find the direction of the meteor shower radiant point, and then wait and see." Li Geng said, due to the influence of ground light, moon light, etc. In fact, people seem to have fewer meteors than ZHR, so watching a meteor shower requires a little patience and luck. (Finish)