Is the Big Dipper expired now, and is the Big Dipper a celestial system

The Beidou Satellite Positioning System (BDS) is a regional navigation and positioning system established by China. The system consists of four (two working satellites and two standby satellites) Beidou positioning satellite (Beidou-1), the ground control center as the main ground component, and the Beidou user terminal. The Beidou positioning system can provide users with all-weather, 24-hour real-time positioning services, with a timing accuracy of tens of nanoseconds (ns), a three-dimensional positioning accuracy of about tens of meters, and a timing accuracy of about 100ns.

The GPS three-dimensional positioning accuracy of the United States has been increased from 16M to 6M, and the C A code has been increased from 25-100M to 12M, and the timing accuracy is about 20ns. The Beidou-1 navigation and positioning satellite was researched and manufactured by the China Academy of Space Technology. The launch times of the four navigation and positioning satellites are:

31 October 2000; 21 December 2000; 25 May 2003 and 14 April 2007, p.

Three or four are backup satellites. During the 2008 Beijing Olympic Games, it played a "double insurance" role together with the existing GPS satellite positioning system in terms of positioning and monitoring of traffic and venue safety.

Scrapped satellites are usually disposed of in two ways, one is to slow down the malfunctioning satellites, let them fall back to Earth, and burn out in the atmosphere during re-entry. Another approach is to push a malfunctioning satellite into a higher orbit so that it can orbit the Earth for hundreds of years, away from other normal satellites.

When preparing to dispose of the near-orbiting satellites that are about to be scrapped, space engineers slightly change their orbits to put them into a lower orbit (which remains after completing the mission) for more than 25 years before returning to Earth and burning up in the atmosphere in the process. This is the "25-year rule" of Sputnik

Enter the orbit of an abandoned satellite or crash directly into the atmosphere.

were all beaten down as an anti-satellite ** target target...

I would also like to buy a Suzuki'Tangled'Let's buy it later.

They all belong to the constellation Ursa Major, but they are not the same celestial system, because the celestial system is a system composed of interacting celestial bodies, such as the Earth-Moon system and the solar system. The Big Dipper, on the other hand, only looks very close to the eye from Earth, but the actual distance is tens of light-years apart.

Below is the distance from the Big Dipper to Earth, and the distance between them can be seen.

Star Name Ancient Name English Name Bayer Stellar Nomenclature Visibility Distance (light years) Tianshu Greedy Wolf Dubhe Uma 124 Tianxuan Giant Gate Merak Uma 79 Tianji Lucun Phecda Uma 84 Tianquan Wenqu Megrez δ Uma 81 Yuheng Lian Zhen Alioth Uma 81 Kaiyang Wuqu Mizar Uma 78 Yaoguang Broken Army Alkaid Uma 101

The Big Dipper is part of the constellation Ursa Major, and graphically, the Big Dipper is located on the tail of the Ursa Major. Five of these seven stars are of the 2nd magnitude and 2 are of the 3rd magnitude. Through the connection of the two stars in the bucket mouth, it is extended about 5 times in the direction of the bucket mouth, and the North Star is found.

The song of recognizing the stars has: "Recognizing the stars first comes from Beidou, and then from the north to the west." "Beginners can learn to recognize the stars from the Big Dipper, in turn, the Big Dipper.

It's time to find other constellations. 7 stars in the shape of a spoon in the constellation Ursa Major. The ancients attached great importance to Beidou because it could be used to identify directions and determine the seasons.

The four stars of Tianshu, Tianxuan, Tianji, and Tianquan are the kui, forming the "bucket" of the Big Dipper, and the handle-shaped three stars are respectively Yuheng, Kaiyang, and Yaoguang, the light and dark stars. The star name of the dipper** is "Kaiyang", and there is a 4th degree companion star 11 minutes away, named "Fu", and the Kaiyang star and the auxiliary star form an apparent double star, which can be identified by the naked eye. Kaiyang itself is also a double star.

Depending on the season, the position of the Big Dipper in the sky is also different. Therefore, the ancient people of our country determined the seasons according to the change of its position. "Ganshi Star Sutra":

The Big Dipper is called the Seven Politics, the princes of the sky, and the emperor car. "The emperor sat on the Big Dipper to inspect the four directions, set four hours, and divided the cold and summer. The ancient book "Crane Crown" records:

Dou Dipper East refers to the fact that the world is spring; Dipper south refers to the fact that the world is summer; Dipper refers to the west, the world is autumn; The north of the dipper refers to the winter in the world. "In ancient times, the North Star was regarded as a symbol of God, and the Beidou was the royal chariot driven by God to patrol the world, and the year began in spring, and at this time the Beidou was in the east, so God began to patrol from the east, so "Yi. Biography:

The emperor was shocked by the shock", and the hexagram was in the east. [1] Among the seven stars of the Big Dipper, "Yuheng" is the brightest, and its brightness is almost close to that of a first-magnitude star. "Tianquan" is the darkest and is a third-magnitude star.

The other five are all second-class stars. In the vicinity of "Kaiyang" there is a small companion star called "Fu", which has always attracted people's attention with its beautiful and clear appearance. It is said that when the ancient Arabs recruited soldiers, they used it as a "test star" to test the eyesight of soldiers.

The Big Dipper is always moving slowly in relative motion in the sky. Five of the stars move in one direction at roughly the same speed, while the "Celestial Pivot" and "Shaking Light" move in opposite directions. Therefore, in the long cosmic transition, the shape of the Big Dipper will change greatly, and after 100,000 years, we will not be able to see this shape of the dipper.

Also known as "Beidou". Not far from the North Celestial Pole, seven bright stars are arranged in the shape of a bucket (see picture). Except for the δ (Tianquan) star, which is a 3rd magnitude star, the other six stars are all 2nd magnitude stars.

The North Star can be found by connecting the two stars in front of the Big Dipper and extending the distance in the direction of the mouth of the bucket by about five times, and is often used as a sign to indicate direction and identify constellations.

At 23:33 on October 25, 2012, China successfully launched the 16th Beidou navigation satellite into the predetermined orbit with the "Long March-3C" rocket at the Xichang Satellite Launch Center. This is the last satellite of China's second-generation Beidou navigation project.

The official clear statement is that there are 16 pills, and you can check the information to confirm.

The Beidou Satellite Positioning System (BDS) is a regional navigation and positioning system established by China. The system consists of three (two working satellites and one backup satellite) Beidou positioning satellite (Beidou-1), the ground control center as the main ground component, and the Beidou user terminal.

The space end includes 5 geostationary orbit satellites and 30 non-geostationary orbit satellites.

The Beidou Navigation Satellite System is composed of three parts: space segment, ground segment and user segment, which can provide high-precision and high-reliability positioning, navigation and timing services for all kinds of users around the world, and has the ability of short message communication.

On June 23, 2020, the last global networking satellite of Beidou-3 was ignited at the Xichang Satellite Launch Center.

In the past 20 years, the Long March rocket has been launched as the only carrier of the Beidou satellite as many as 44 times, and has successively sent 4 satellites of the Beidou-1 system, 20 satellites of the Beidou-2 system, and 35 satellites of the Beidou-3 system into space.

At 5 o'clock on July 27, 44 minutes later, China successfully sent the ninth Beidou navigation satellite into the predetermined transfer orbit of space with the "Long March-3A" early carrier rocket at the Xichang Satellite Launch Center.

In January 2012, 2 (one arrow and two satellites) were launched, pay attention to secrecy...

It seems that it is still in the experimental stage and has not been put into civilian personal clients.

Just as big. The Big Dipper is very far away from the Earth and does not change in size due to the movement of the Earth. Even if there is change, it is negligible. Because, this is not visible at all.

Because of the distance, no natural factor on Earth can affect the size of Ursa Major, that is, the Beidou in the eyes of man

。。。Due to the Earth's revolution, the constellation Ursa Major will be near and far...

Generally, the Big Dipper we see in summer, that is, the "spoon", will be "bigger", and it should be that the Earth is a little closer to the constellation Ursa Major.

And in winter, the Big Dipper will be slightly smaller...

What do you mean?

The upstairs is wrong. The constellation Ursa Major is just an artificially divided celestial region, and the distances of the individual stars in it vary greatly. If it's because of the change in distance, then the change in its size is definitely uneven.

In fact, the change in two astronomical units is of little practical significance relative to such a distant distance measured in light years.

It's the same size.

The distribution of the stars in the sky that we observe is their projection of the surface of a celestial sphere, which we can say as an artificial hypothesis, and each star is close to each other, not really close or far, and we think that some two stars are close only because they appear close to the surface of our "celestial sphere".

The shape of the visual distance between certain stars that we see will only change due to their respective movements over the years, and because the distance between the stars we see is so large relative to their moving speed, it is a rather long process for us to visually see their relative positions change, and thousands of years is not too long.

The rotation of our earth is too small and small for this vast radius of the celestial sphere, and the arrangement of the stars will hardly change at all.