Poster Maker: Feng Juan
People can only see the five planets with the naked eye on Earth, of which Mercury is the most difficult to observe because it is too close to the sun. Only when the distance is large can people expect to witness its "figure".
According to astronomical science experts, the last large distance of Mercury this year will be staged on October 25, and this large distance is the west distance, and the observation conditions are good.
At that time, as long as the weather is good, about a week before and after the large distance, interested publics will be low in the east in front of the sunrise, and with the naked eye or with the help of binoculars, it is expected to catch a glimpse of Mercury's "true appearance".
Tianjin astronomy enthusiast Wang Qiang photographs Mercury a few days after Dongda on February 16, 2020. (Courtesy of me)
Of the eight planets in the solar system, Mercury and Venus are known as intra-Earth planets because their orbits are within the Orbit of the Earth.
When an inner planet is tangent to the earth's connection to the earth and the orbit of an earth planet, it is called a large distance. The large distance is divided into the east distance and the west distance.
"Because from Earth, at this time the earth's planets have the largest angular distance from the sun. Since Mercury has a maximum angular distance of 28 degrees from the Sun and Venus has a maximum angular distance of 48 degrees from the Sun, they can only be seen in the eastern sky before sunrise or in the western sky after sunset, or they can only be seen as morning or evening stars. Xiu Lipeng, director of the Tianjin Astronomical Society and an expert in astronomical science popularization, said.
Mercury photographed by the U.S. Courier Mercury probe. (Image source: NASA official website)
Mercury's orbital period is the shortest of the eight planets, about 88 days, and the rendezvous period with Earth is about 116 days. Each rendezvous period occurs once in the East and One Great West, so most years there will be 6 Mercury Macros.
"This year Mercury has a total of 6 large distances, 3 times each in the east and west distances. For the Northern Hemisphere, there were three good observations, including this one. At this large distance, mercury can reach an angle of 18 degrees from the Sun, and the horizon height at sunrise is about 17 degrees, and the brightness is about -0.5. Xiu Lipeng said.
Close-up of Mercury taken by Beijing astronomy enthusiast Zong Haiyang on February 9, 2020. (Courtesy of me)
So, how can Mercury be better observed? Xiu Lipeng suggested that we should first find a place with a wide field of view, and then use the star map software to simulate the operation information of Mercury and the sun to find their location.
It is recommended that the Sun look for mercury observations at 6 degrees below the horizon, when Mercury's horizon altitude is about 11 degrees. Influenced by the morning atmosphere, Mercury will look a little darker than it actually is, and it is susceptible to the thin clouds commonly found at low altitudes, and binoculars can be used to assist in the search.
A close-up of Mercury taken by Tianjin astronomy enthusiast Wang Shuo on May 18, 2021. (Courtesy of me)
"It should be noted that the observation time of the telescope should be strictly controlled, and the observation must be stopped before sunrise, and the telescope should not be aimed at the sun and nearby celestial bodies, which can easily lead to permanent damage to the eyes." Xiu Lipeng specially reminded.
Producer: Zhao Cheng
Producer: Hu Qinghai
Planner: Liu Xinhui
Reporter: Zhou Runjian
Edit: Chonghai
It was jointly produced by Xinhua News Agency and Tianjin Branch of Xinhua News Agency
Produced by Starry Sky Studios
Source: Xinhua News Agency