Gaia's full name is Astrophysics Global Astrometry Interferometer Satellite. The project was initiated by the European Space Agency and headed by Danish scientist Eric Hogg. A large part of Gaia satellite is produced and assembled by AS Triem Company in Toulouse. It was launched by Russian Soyuz carrier rocket at Kourou launch base in French Guiana, South America in February 20 13.
We are far away from the time when astronomers observed the sky with naked eyes through small telescopes. At present, astronomical research is often the result of large-scale international team cooperation, and Gaia satellite project is a model of global scientist cooperation. All the data will be preliminarily processed by an international laboratory alliance and released to scientists and laboratories all over the world. Now, three batches of data have been released. Recently, the research team of Purple Mountain Observatory of China Academy of Sciences used the third batch of early data of Gaia to search for more than 700 new open cluster candidates.
In Greek mythology, the birth of Gaia marked the beginning of chaos from disorder to order. Through Gaia satellite, humans can measure the position, distance and trajectory of billions of celestial bodies more accurately, from asteroids to all stars in the sky to galaxies. The number of stars that humans can accurately measure the distance, from about 6,000 before the space age to hundreds of thousands with the help of 1989 Iba Valley satellite, and now to billions.
Gaia satellite weighs only about 2 tons, carries two telescopes and three measuring instruments, and can detect celestial bodies with a galactic coefficient of one billion. Each celestial body will be observed about 60 times, and people will be able to analyze the movement of these celestial bodies in space like never before.
What will all this bring us? First of all, we can better understand the universe. Astrophysicists all over the world will be able to draw accurate three-dimensional maps of the sky. This is to restore the true positions of stars and galaxies in the sky through the returned data, rather than their positions in our eyes. For example, the spoon-shaped "Big Dipper" in our traditional impression is actually not on the same plane and is far from the earth.
Secondly, we can better understand the structure and evolution of the Milky Way. The data set of Gaia satellite for many years describes the detailed motion of about 654.38 billion stars. Some researchers have speculated on the formation process of the Milky Way by tracking and studying the trajectory of ancient stars, which has changed people's previous cognition. "Gaia started a new revolution." Federico Stito, an astronomer at the Strasbourg Observatory in France, said.
In addition, we can classify asteroids more reasonably and track them more closely. In literary works, there are often doomsday scenes of asteroids hitting the earth. Although the probability of this happening is extremely low in the actual situation, it is still necessary to establish a monitoring system to accurately warn asteroids that may pose a threat and take defensive measures. Through Gaia satellite, these asteroids will be better recorded and contribute to better risk management.
It can be said that Gaia satellite is a landmark project in the history of astrometry, and it is also the project with the highest implementation accuracy so far. In addition to searching for quasars and compact objects more efficiently, Gaia can also provide key data such as distance and motion for the structure and dynamics of the Milky Way and the formation and evolution of stars. Its milestone is not only in the field of astrometry, but also in the field of human cooperation around the world.
Gaia satellite is expected to release three phases of data in 2022, and then retired. It changed astronomy and our understanding of the surrounding space. We are confident that in the future exploration of the universe, there will be more satellites with better performance, such as Euclid and China's China Space Station Engineering Survey Telescope to be launched by ESA in the second half of 2022. The pace of human exploration of the starry sky will not stop there.
refer to
Sylvie walker. Dialogue with the universe [M]. Beijing United Press, 20 19. Page 69-765438 +0.
2 1202 12993 You Congjie (instructor Wen Xin)
May 3(rd), 2022