The Shanghai Planetarium (Shanghai Science and Technology Museum Branch) will officially open on July 17 and welcome the public from July 18. In the planetarium, the world's largest planetarium, there are about 70 famous meteorites that tell the story of the universe and lead the audience to open the "Covenant of the Stars".
【Meteorites hide the mysteries of the universe】
Where do meteorites on Earth come from? According to experts, there are countless fragments scattered in space, or as thin as dust, or as large as boulders, known as meteoroids. When meteoroids fly into the Earth's atmosphere at high speed, they rub violently against the atmosphere, producing a bright glow. Among them, the smaller meteoroids will burn out in the atmosphere, and the remnants of the larger meteoroids will fall to the ground and become meteorites. According to experts, dozens of tons of space debris fall on Earth every day.
These "extraterrestrial visitors" are precious — people don't have to travel to space to get samples to study the universe. Lin Qing, director of the Astronomical Research Center of the Shanghai Science and Technology Museum, said that most of the meteorite mothers are more than 4.5 billion years old, they have been in cold space for a long time, the original structure has not been destroyed, and the information at the beginning of the formation of the solar system is well preserved. "By studying minerals such as silicate chondrites and calcium-aluminum inclusions in meteorites, we can unearth the secrets of the formation and evolution of the solar system."
Meteorite "family". Photo by Xinhua News Agency reporter Chen Aiping
[The number of stone iron meteorites is less than 1%, which is very rare]
According to experts, if you look at the chemical composition, meteorites can be divided into stony meteorites, iron meteorites and stony iron meteorites. Among them, stony meteorites are the most common meteorites, accounting for about 95% of the total number of meteorites, mainly composed of silicate minerals such as olivine and pyroxene, according to whether they also contain spherical structures of microns to millimeters, stony meteorites can be divided into chondrite meteorites and non-chondrite meteorites. Iron meteorites are mainly composed of iron-nickel metals and their sulfides. Stony iron meteorites are mainly composed of iron-nickel metals and silicates, and their number is less than 1% of the total number of meteorites, which is very rare.
The East Uzumuqin Banner meteorite on display in the museum fell over the East Uzumuqin Banner area of Inner Mongolia in September 1995. This is a rare iron meteorite in the subcategory of stony iron meteorites, with a beautiful large-grained metal nodule-like structure in the section and a brecculate olivine crystal visible locally.
East Uzumuqin Flag meteorite. Photo by Xinhua News Agency reporter Chen Aiping
[These meteorites are not easy to come by and should not be missed]
The arrival of meteorites can be a "sensation". There is a sixth station meteorite in the Shanghai Planetarium, don't look at it is only 71 grams, its appearance is not proud, but it is the first time that humans, and the only time to date to track the asteroid to the earth and retrieve one of the meteorite specimens - in 2008, the asteroid 2008TC3 exploded over the Sudanese Nubian Desert, forming a meteorite scattering area, and finally people collected a total of 3.95 kilograms of specimens in the area, and the sixth station meteorite was one of them.
Sixth station meteorite. Photo by Xinhua News Agency reporter Chen Aiping
The Changxing meteorite is the only recorded sighting of a meteorite in the Shanghai area. The largest of the 21.4 kilograms in the collection, the meteorite surface is wrapped in a black molten shell with airmarks and molten veins. When it fell in 1964, it smashed through a farmhouse and knocked the ground beneath the farmhouse into a large pit half a meter in diameter.
Changxing meteorite. Photo by Xinhua News Agency reporter Chen Aiping
The "crater" of Mangui in the collection of the Shanghai Planetarium records the moment of the arrival of the meteorite. In 2018, there was a meteorite rain in Yunnan, and hundreds of meteorites were scattered around Mengcha Town, the largest of which fell into a tea garden in the local village of Mangui, forming a small meteorite impact hole with a diameter of 13 centimeters and a depth of 25 centimeters on the ground. Lin Qing introduced that most of the craters are easy to be destroyed after formation, or the crater is too large to be suitable for collection and display, and this Mangui "crater" is well preserved and of moderate size, which is very rare.
Mangui "Crater". Photo by Xinhua News Agency reporter Chen Aiping
【The meteorite collection is of the world's first-class level, worth seeing】
Meteorites may be scattered in noisy cities, rural areas, or in silent and uninhabited areas. According to experts, the cold and dry climatic conditions in the Antarctic region are conducive to the preservation of meteorites, and the movement and melting of glaciers over millions of years have formed a special meteorite enrichment mechanism. In 1912, the Oceania Antarctic Expedition first discovered meteorites in Antarctica. With the advancement of China's polar scientific expeditions, China has gradually become one of the countries with the largest number of meteorites collected in Antarctica.
Du Zhimao, head of collection business at the Shanghai Planetarium, said that because meteorites are scattered around the world, the collection of the Shanghai Planetarium has continued for many years before the opening of the museum. The "post-80s" expert has traveled around the world in the past 5 years to find precious meteorites and other collections, and the number of air miles alone is nearly 120,000 kilometers, "to continue to accumulate experience, as many representative meteorites as possible to find representative meteorites, play a role in science popularization, and choose some 'treasures of the town hall' with potential scientific research value to support scientific research work." ”
Today, the Shanghai Planetarium has a collection of about 70 famous meteorites and more than 120 pieces/sets of cultural relics, reflecting the world-class collection standard in the field of astronomy. "The Shanghai Planetarium is one of the windows to show the progress of China's astronomical research and the history of a space power, and contributes to the Chinese dream of building a scientific and technological power through popular science education." Wang Lianhua, secretary of the party committee of the Shanghai Science and Technology Museum, said.
Producer: Zhao Cheng
Producer: Hu Qinghai
Planner: Liu Xinhui
Text: Chen Aiping, Ding Ting, Fang Zhe
It was jointly produced by Xinhua News Agency and Shanghai Branch of Xinhua News Agency
Produced by Starry Sky Studios
Source: Xinhua News Agency