Science and Technology Daily reporter Tang Fang
Looking back at the vast starry sky in 2021, the Chinese nation burst into the most dazzling splendor: "Tianwen" climbs the fire, "Xihe" explores the sun, "Milky Way" sky survey, "Tiangong" view victory...
This year, the large-scale scientific project to explore the information of the universe was also fruitful. The "China Sky Eye" discovered 201 pulsars and the "Lasso" observed the highest energy photons, which shocked the international astronomy community; Chang'e 5 brought back to the moon "earth". "Special products, opened a new chapter in my country's lunar scientific research...
The Chinese nation is making great strides on its journey to explore the sea of stars and stars.
01
"Tiangong" construction is in full swing
my country's manned spaceflight enters the "space station era"
The space station, the "space home" for astronauts, and the "space laboratory" for scientific research.
At 11:23 on April 29th, at the Wenchang Space Launch Site in Hainan, the Long March 5B high-thrust carrier rocket successfully sent the core module of the Chinese Space Station into space with a huge amount of force. my country's manned spaceflight truly ushered in the space station era.
At this point, the orbital assembly and construction of the Chinese Space Station has been fully launched.
The China Space Station is a manned space station independently constructed and operated by China. It operates for a long time in low-Earth orbit. It relies on cargo spacecraft to supplement propellants and consumables. It can meet the needs of astronauts for long-term life and work in orbit. Comprehensive, most complex, most advanced and most comprehensive scientific and technological achievements.
On June 17, the astronauts Nie Haisheng, Liu Boming, and Tang Hongbo carried by the Shenzhou 12 manned spacecraft entered the Tianhe core capsule successively, marking the first time the Chinese entered their own space station; on October 16, the Shenzhou 13 spacecraft The human spacecraft successfully sent Zhai Zhigang, Wang Yaping, and Ye Guangfu into space. After stationing in the Tianhe core module, it opened a 6-month space residence; on November 7, Zhai Zhigang and Wang Yaping successfully exited the node module of the Tianhe core module. Wang Yaping took the first step of a Chinese woman's extravehicular spacewalk; on December 9, the crew of Shenzhou 13 astronauts gave space lessons for the first time at the Chinese Space Station.
02
Discovered that the anti-yalxinzi structure originated from the silver plate
Terminating the dispute over the origin of the substructure
Astronomers already know that the Milky Way is not a smooth flat disk as traditionally understood, but a galaxy of rippling stellar waves.
This understanding stems from the discovery of the anti-galactic substructures of the Milky Way, but there is controversy about where these substructures originated.
In May, a research paper by Chinese scientists published in Astrophysical Journal put an end to this controversy.
Researchers from the National Astronomical Observatory of the Chinese Academy of Sciences, China West Normal University and other units used the Guo Shoujing Telescope (LAMOST) and Gaia satellite (Gaia) data to perform "paternity test" on some sub-structures and silver plates located in the direction of the anti-galactic center. , Found that the anti-galactic substructure of the Milky Way is not a remnant of a dwarf galaxy accreted by the Milky Way, but a part of the outer disk of the Milky Way.
Using the observation data of the telescope, the researchers searched for 589 member stars from the Monoceros ring, the Triangulum-Andromeda star stream and the A13 structure. This is the largest sample of members of the antigalactic substructure at present.
The researchers compared the chemical element content, motion characteristics, and energy angular momentum distribution of the member star samples with the silver disk, and found that these member stars and the silver disk have similar nearly circular motion orbits, and the metal abundance is proportional to the thickness of the silver disk. The disk stars are similar, and these all prove that the substructure member stars may come from the thick disk of the silver disk.
However, further verification found that the alpha element abundance of these substructure member stars was significantly lower than that of the thick disk.
In this regard, Li Jing, an associate professor in the School of Physics and Space Science at China West Normal University, explained that because there are still a lot of cold gas in the outer disk of the Milky Way, the molecular cloud density of the outer disk is low compared to the inner disk, and the metal abundance of chemical elements has not increased sufficiently.
From the motion characteristics and chemical DNA identification, astronomers speculate that these substructure member stars should belong to low alpha abundance metal-poor outer disk stars.
Xue Xiangxiang, a researcher at the National Astronomical Observatory of the Chinese Academy of Sciences, said: "This means that these anti-silver core structures originated from the silver disk."
03
Tianwen-1 landed on Mars
Exploring clues to the origin and evolution of Mars
Crossing the Long Star River, trek for 297 days. At 7:18 on May 15, 2021, the speed of more than 20,000 kilometers per hour was reduced to zero in just 9 minutes. The Tianwen-1 Landing Patrol successfully landed on the southern Utopia Plain of Mars. In the area, my country’s first Mars exploration mission to Mars achieved a complete success.
At 10:40 on May 22, the "Zhu Rong" rover safely drove away from the landing platform, reached the surface of Mars, and began to patrol and explore.
China became the second country in the world to successfully land a Mars rover.
Zhang Rongqiao, chief designer of my country’s first Mars exploration mission project, introduced that the Tianwen-1 mission is the first step for China to carry out planetary exploration. It has successfully completed the established mission goal of "realizing Mars circumnavigation, landing, and patrol in one mission", which will greatly promote it. China's space science, especially the development of planetary science research.
At present, Tianwen-1 is operating well in orbit, and all 13 scientific payloads have been started to carry out scientific exploration activities, providing scientists with abundant high-quality scientific exploration data.
Specifically, multi-element, first-hand scientific data on Mars including Martian topography, surface material composition, underground structure, magnetic field, weather and space environment, etc. can be obtained.
The "Zhurong" is continuing to drive towards the suspected junction of ancient ocean and land in the southern Utopia Plain, seeking clues to the mystery of the origin and evolution of Mars.
It is worth mentioning that Tianwen-1 also acquired a group photo of the earth and the moon, "deep space selfie" flying images, and sent back the first image of Mars during its rush to the fire.
After reaching the surface of Mars, on June 11, the first batch of scientific images of Tianwen-1 was released, marking the complete success of my country's first Mars exploration mission.
04
"Lasso" discovered the highest energy photon to date
Break through the traditional understanding of human beings on the acceleration of particles in the Milky Way
The High Altitude Cosmic Ray Observation Station "LHAASO" (LHAASO), located in Haizi Mountain with an average altitude of 4410 meters in Daocheng, Sichuan, is the world's largest high-altitude cosmic ray observation device. It lasted 4 years and was completed on October 24. And officially entered the stage of scientific operation.
The "pull cable", which was operating while building, discovered photons with an energy of 1.4 PeV in the Milky Way.
This is the highest energy photon ever observed by mankind, breaking through mankind's traditional cognition of particle acceleration in the Milky Way, and ushering in a new era of ultra-high energy gamma astronomy.
On May 17, related papers were published online in the journal Nature.
05
FAST discovers 201 pulsars
"China Sky Eye" has become the most powerful pulsar search tool
Pulsars are the "remains" after the death of massive stars. They can emit highly periodic pulses with a period between 1.4 milliseconds and 23 seconds. The short-period pulsars called "millisecond pulsars" can interact with the earth. The best atomic clock is comparable.
Therefore, pulsars are one of the main scientific targets observed by large international radio telescopes.
As of April 2021, Chinese scientists have used the 500-meter spherical radio telescope (FAST) to conduct sky surveys, and newly discovered 201 pulsars, including a batch of the weakest pulsars, and the large dispersion that challenges contemporary electronic distribution models of the Milky Way. Quantitative pulsars, 40 millisecond pulsars, 16 pulsars, a batch of mode change and zero-elimination pulsars, and radio transient sources.
Related research results were published as a cover article in "Astronomy and Astrophysics Research" on May 20.
FAST is known as the "Chinese Sky Eye" and is equipped with 19-beam L-band receivers. It is the world's most powerful pulsar search tool.
"Subsequent time observations of these pulsars can be used to detect low-frequency gravitational waves from distant galaxies, and can also be used to establish pulsar time and space benchmarks. Some of these pulsars will become excellent tools for testing the theory of gravitation." China Said Han Jinlin, a researcher at the National Astronomical Observatory of the Academy of Sciences.
06
Distribution of lunar samples of Chang'e 5
It is expected to reveal the mystery of the evolution of the moon and planets
Observe one gram of the lunar soil up close, and remotely measure the galaxy for thousands of years.
Lunar soil is formed by space weathering such as long-term meteorite and micrometeorite impacts, solar wind, and cosmic ray radiation from moon rocks on the surface of the moon.
In addition to reflecting the material composition of the moon's surface itself, the lunar soil is also an important carrier for recording the history of interaction between the solar wind and the moon's surface and the proliferation of foreign matter.
On July 12, the launch ceremony of the first batch of lunar scientific research samples of the Chang'e-5 mission was held.
31 applications from 13 scientific research institutions were approved, and a total of 17.4764 grams of samples were issued. The scientific research on lunar samples was officially launched.
On October 20, the list of the second batch of lunar scientific research samples was released, and a total of 17.936 grams of samples were distributed.
Researchers will use the lunar soil to conduct research on the lunar surface process, the age of volcanic activity, and the evolution of the moon. It is hoped that they will have new insights into the evolution of the moon and planets, and the habitability of planets.
The lunar samples of Chang'e 5 soon produced the first batch of scientific research results.
On October 19, researchers from the Institute of Geology and Earth Sciences of the Chinese Academy of Sciences and the National Astronomical Observatory discovered that the lunar sample of Chang'e-5 is a new type of lunar basalt.
The “youngest” basalts on the moon are 2 billion years old. The source area of late magmatic activity in the area is not rich in radioactive elements, and there is almost no water in the lunar mantle source area.
On December 13, the Purple Mountain Observatory of the Chinese Academy of Sciences and the Nanjing Institute of Geology and Paleontology discovered that the lunar sample contains extremely high ilmenite and is a high-titanium basalt.
Previously, other domestic research teams have found low- and medium-titanium basalt types in lunar samples.
Researchers speculate that there may have been multiple volcanic eruptions in the lunar landing zone of Chang'e 5.
07
Suborbital reusable vehicle made its first flight
my country from a space power to a space power
The development of reusable space and earth transportation technology is an important symbol of my country's transformation from a space power to a space power.
The suborbital reusable carrier can be used as a sub-level of the lift-type rocket power reusable space transportation system, and it is a highly fusion of aerospace technology.
On July 16, the sub-orbital reuse demonstration and verification project carrier developed by the First Academy of China Aerospace Science and Technology Corporation ignited on time at the Jiuquan Satellite Launch Center. After completing the flight according to the set procedure, it landed smoothly in Alxa Right Banner. At the airport, the first flight mission was a complete success.
Yang Yuguang, a researcher at the Second Academy of Aerospace Science and Technology of China, said that the minimum height of the suborbital apogee is 80 to 100 kilometers, and theoretically it can reach the edge of the earth's gravitational force, that is, 1.5 million kilometers.
The trajectory of the passive section of the ballistic missile with a longer range is the suborbit.
Suborbital is also widely used in sounding rockets and space tourism.
08
World-class observatory site found in Lenghu, Qinghai
Will become an extremely valuable strategic scarce resource in our country
Optical/infrared observation sites are extremely valuable strategic and scarce resources. The only internationally recognized best sites are the mountainous areas in northern Chile, the Monakaya Peak in Hawaii, and the inland ice dome of Antarctica.
On August 18, "Nature" published a major scientific progress on the site selection of astronomical observatories in my country. After 3 years of continuous monitoring, the research team of Deng Licai of the National Astronomical Observatory of the Chinese Academy of Sciences found that the optical observation conditions of the Qinghai Lenghu Observatory were comprehensively excellent. Other sites on the Qinghai-Tibet Plateau can be compared with the best internationally recognized observatory sites.
The cold lake area has abundant sunshine, little precipitation, and clear night sky. The historically recorded weather conditions are very good.
Deng Licai’s research team conducted a field visit to the Saishiteng mountain area in Lenghu and determined to select a site at an altitude of 4,200 meters (Saishiteng C area) in the mountain area. Since 2018, the number of clear nights and the background of clear nights in this area will be officially selected. Brightness and weather have been continuously monitored for 3 years. At the end of 2020, conclusive data on the optical/infrared observation conditions of the Saisten Mountain will be obtained.
In order to maximize the scientific benefits of the cold lake site, Deng Licai stated that the site resources should be protected as soon as possible to avoid the influence of light, dust, vibration and other factors; it should also attract internationally leading observation facilities to settle down and make it a An important base for international optical astronomy research.
09
"Xihe" launch
my country's breakthrough in achieving zero solar detection
The sun is the closest star to the earth, which is of great significance to the evolution of the earth and the development of human civilization.
On October 14, my country’s first solar exploration science and technology experimental satellite "Xihe" was successfully launched. my country officially entered the era of "sun exploration" and achieved a breakthrough in solar exploration.
The full name of "Xihe" is the solar Hα spectrum detection and dual super-platform scientific and technological experimental satellite. It weighs 508 kilograms and has a design life of 3 years. It operates in a sun-synchronous orbit with an altitude of 517 kilometers and can observe the sun continuously for 24 hours. , The main scientific payload is the solar space telescope.
From launching "cars" to satellite platforms to scientific payloads, "Xihe" has created many "firsts": the first international space exploration of solar Hα band spectral imaging; the first use of "moving and static isolation non-contact" overall design new Method: For the first time, a new method of "active control of the payload bay and slave control of the platform bay" is proposed; for the first time, the application of satellite high-power, high-reliability, and high-efficiency wireless energy transmission technology is realized.
10
"Galaxy Picture Scroll" Phase II Sky Survey Project Launched
Will provide a wider area of molecular gas distribution data
Sky survey is a basic method for humans to explore the information of the universe. It is a systematic observation method that scans the scannable area of the sky block by block indiscriminately, and discovers unknown celestial bodies by conducting a "general survey" of the sky.
The "Galaxy Picture Scroll" sky survey project is the only sky survey project in the millimeter wave band in my country. It uses the 13.7-meter millimeter wave radio telescope in Delingha, Qinghai for astronomical observations.
In November this year, the 10-year “Galactic Picture Scroll” phase II sky survey program was launched, extending the sky survey area to a range of plus or minus 10 degrees latitude near the galactic plane, which will provide a wider range of molecular gas distribution for multi-band astronomical research data.
The first phase of the "Galaxy Picture Scroll" sky survey project lasted 10 years from November 2011 and ended at the end of April 2021. It completed the detection coverage of 2400 square degrees in the range of plus and minus 5 degrees of silver latitude, and established a millimeter wave molecular spectrum database. .
Yang Ji, a researcher at the Purple Mountain Observatory of the Chinese Academy of Sciences and the head of the "Galaxy Picture Scroll" survey project, pointed out that whether it is the first or second phase of the project, the "carbon monoxide molecular spectrum" is the core of the "Galaxy Picture Scroll" project because it can help. Scientists reveal the temperature and density of molecular gases.
At present, there have been several influential astronomical survey projects in my country. In addition to the "Galaxy Picture Scroll" project, there are also spectral surveys based on LAMOST and pulsar surveys based on FAST.