Poster Maker: Feng Juan
According to astronomical science experts, on October 30, the east distance of Venus will occur, at that time, the brightness of Venus is about -4.6 and so on, which is brilliant and very eye-catching. With binoculars or small astronomical telescopes, interested members of the public can also enjoy the enchanting figure of Venus like a small moon.
Beijing astrophotography enthusiast Zong Haiyang photographed the Venus cloud belt and phase changes from January to April 2020 (multiple superpositions). (Courtesy of me)
Venus is the close neighbor of the earth, which was called "too white" in ancient China. When it appears in the morning, people call it "daystar" or "morning star"; when it appears at dusk, people call it "Chang Gung Star" or "Evening Star".
Typically, Venus is the brightest object of the day except the Sun and Moon, with a maximum brightness of -4.9 magnitudes.
Beijing astrophotography enthusiast Tang Bo photographed "Venus and Jupiter" in Beijing on November 24, 2019. (Courtesy of me)
Song Yuanyuan, director of the Tianjin Astronomical Society and an expert in astronomy science at the Tianjin Science and Technology Museum, said that in most cases, Venus is very bright when observed on the earth, and the brightness exceeds -4. Because it is somewhat farther away from the Sun than Mercury, it will be easier to observe.
The so-called east (or west) distance of Venus refers to the fact that Venus is on the east (or west) side of the Sun, and from the Earth, Venus has the largest opening angle with the Sun.
Beijing astrophotography enthusiast Tang Bo photographed "Venus and Mercury" in Beijing on May 23, 2020. (Courtesy of me)
Venus' orbital period is about 225 days, and the rendezvous period with Earth is about 584 days, so the interval between the two adjacent west or east distances is about 19 months.
The time interval between Venus from the west to the east is long, about 440 days, while the distance from the east to the west is short, only about 140 days.
This results in a minimum of 0 and a maximum of 2 venus large distances per year.
Also the inner planet, Mercury is more common. Mercury has an orbital period of about 88 days and a rendezvous period with Earth of about 116 days.
Each rendezvous period occurs once in the east and one large distance in the west, so there will be 6 Mercury macros in most years and 7 in very few years.
Beijing astrophotography enthusiast Wang Junfeng photographed the trajectory of Venus (brighter) and Mercury after sunset on May 23, 2020. (Courtesy of me)
Since the end of March this year, Venus has begun to change from "morning star" to "evening star", and since then, the angular distance from the sun has been increasing, and it is easy to find its traces in the low western sky after sunset in July, which perfectly interprets the title of "Chang Gung Star". From August to December, Venus will be brighter than magnitude -4.
Song Yuanyuan said that during this large distance period, the angular distance between Venus and the sun can reach 47 degrees, the horizon height at sunset is about 17 degrees, and the brightness is about -4.6, which shines in the southwest sky, like a bright lamp, which is easily recognizable. For the next two months or so, as long as the weather is clear and every day after sunset, people can observe Venus.
"Interested members of the public who observe Venus for several consecutive days through binoculars or small astronomical telescopes can clearly see that the shape of Venus is the same as that of the moon, and there are changes in circles, sometimes like curved hooks, sometimes like semicircles." Song Yuanyuan said.
Producer: Zhao Cheng
Producer: Hu Qinghai
Planner: Liu Xinhui
Reporter: Zhou Runjian
Edit: Chonghai
It was co-produced by Xinhua News Agency and Tianjin Branch of Xinhua News Agency
Produced by Starry Sky Studios