Sun-Earth Lagrange Point;
L 1 and l2 are1.5000 km away from the earth, l3 and l4 are 1a.u away from the earth, and l5 is 2a.u away from the earth. Lagrangian points of the earth and the moon;
L 1 and l2 are 65,000 kilometers away from the moon and 3,846,500 kilometers away from the earth, respectively, and l3, l4 and l5 are 384,000 kilometers away from the earth 1 month.
There are five Lagrangian points * * *, and most of them are using L2 now. L2 is located on the connecting line between the Earth and the Moon, 445,000 kilometers away from the Earth and 65,000 kilometers away from the Moon. Chang 'e reached L2 on the earth and the sun: 65,438+0,500,000 kilometers from the earth and 65,438+0,500,000 kilometers from the sun.
Extended data:
At a point in space, under the gravity of two large objects, a small object remains basically stationary relative to the two large objects. The existence of these points was deduced by the Swiss mathematician Euler in 1767 and proved by the French mathematician Lagrange in 1772.
1906 It was first discovered that the asteroids orbiting Jupiter (see Trouvat Group Asteroids) were at the Lagrangian point under the action of Jupiter and the sun.
In each system composed of two celestial bodies, it is inferred that there are five Lagrangian points, but only two of them are stable, that is, even if the small celestial bodies at this point are disturbed by external gravity, they often remain in their original positions. Each stable point forms an equilateral triangle with the point where the two main objects are located.
L2, on the connecting line of two big celestial bodies, on the side of the smaller celestial body.
For example, similar effects occur on the other side of the earth. The farther an object is from the sun, the longer its orbital period is usually. The pull of the earth's gravity reduces the orbital period of an object. At L2, the orbital period becomes equal to that of the Earth.
Lagrange L2 point between the sun and the earth: L2 point is located on the connecting line between the sun and the earth, which is about 6.5438+0.5 million kilometers away from the earth. At L2, the satellite can stay for a long time with little fuel. It is an ideal position for detectors and astronomical telescopes to locate and observe the solar system. It has important practical application and scientific exploration value in engineering and science, and is a hot spot in international deep space exploration.
L2 is usually used to place space observatories. L2 objects can be protected and calibrated easily because they can turn their backs on the sun and the earth.
Wilkinson microwave anisotropy probe has been running around the L2 point of the Sun-Earth system. James Webb Space Telescope will be placed at L2 point of the Sun-Earth system. In addition, the world's first communication satellite operating at L2 point in Lagrange, Earth and Moon, and Xingqueqiao relay station, the fourth mission of China's lunar exploration project, will also operate in this orbit.
In addition, Chang 'e-2 satellite left the lunar orbit on June 9, 1965 1 16: 50: 05, and flew to the second Lagrangian point to continue exploration, with a flying distance of 1.5 million kilometers, which is expected to take 85 days.
Beijing time 20 1 1 At 23: 27 on August 25th, Beijing time, after 77 days' flight, Chang 'e II set off from the lunar orbit for the first time in the world and entered the orbit near Lagrange L2, the balance point of gravity between the sun and the earth, about 1.5 thousand kilometers away from the earth.
2014165438+123 October, the service module maneuvered the lunar orbit and flew to L2 point on the earth and the moon. Later, on1October 27th, 165438+ entered the Lissajous orbit around the L2 point of the Earth-Moon, which was the first time that our aircraft flew to the L2 point of the Earth-Moon (instead of the Lagrange point of the Earth-Sun). 1October 28th, June 28th, February 28th, June18th, June18th, and February 26th.
References:
Baidu encyclopedia-la ge lang ri branch