Why Pluto was removed. Previously, we all know that Pluto belongs to one of the nine planets in the solar system, ranking from near to far from the sun. So when was Pluto removed from the list? Let me show you.
I. how was Pluto discovered?
1. In ancient times, people noticed that there were other invisible planets besides the fixed ones. Students who have taken history courses should know Zhang Heng. He was a famous astronomer in the Eastern Han Dynasty. Because of his great contribution, a planet discovered by later generations is called "Zhang Heng star", so as to remember Zhang Heng's great contribution to astronomy in our country.
2. At the beginning of the 20th century, the tyrant astronomer pasivar Lowell believed that he concluded that there was an undiscovered "x planet" beyond Neptune. Ten years after Lowell's death, a 20-year-old farm boy named Clyde TOMBO, born in Kansas, accidentally discovered Pluto.
3. On February 18, 1930, TOMBO was near the ecliptic in Gemini. A light spot that moved significantly in a few days attracted his attention. After calculation, this is a planet more distant than Neptune. It may be the "x planet" that Lowell is hard to find, and it is Pluto.
2. Why was Pluto removed from the list?
Since the discovery of Pluto, it has been controversial by many scientists:
1. Pluto's discovery process is based on a wrong theory;
2. Pluto was wrongly included in the list of big planets because of its wrong mass estimation.
3. Pluto's mass is much smaller than other planets. Even in the satellite world, it can only rank around the seventh and eighth.
4. Pluto's surface temperature is very low, so most of its substances can only be solid or liquid.
5. Pluto's atmosphere is composed of hydrogen, helium and neon. There are no other gas elements, such as oxygen.
6. Recently, at the general assembly of the International Astronomical Union, astronomers voted for a new definition of planet, confirming that there are only eight planets in the solar system, among which there is no Pluto, so Pluto was removed from the list.
7. Among the 12 solar system planets that meet the new definition, Pluto, "Charon" and "2003ub313" all belong to "Pluto like".
III. what is the new definition of planet?
1. The planet must be a celestial body orbiting a star;
2. The mass of the planet must be large enough. Its own gravity must be balanced with the surface force to make its shape a ball. Generally speaking, the diameter of the planet must be more than 800 kilometers and the mass must be more than 5 billion tons.
3. Planets are celestial bodies that can remove other objects near their orbits. According to the new definition, there are only eight planets in the solar system: Mercury, Venus, earth, Mars, Jupiter, Saturn, Uranus and Neptune.
4. A new secondary definition - "Pluto like"
Under the new planetary standard, the planetary definition Committee has also determined a new secondary definition - "Pluto like". This means that the orbit is outside Neptune and revolves around the sun for more than 200 years.
What planet does Pluto belong to now?
Under the new definition of planet by the International Astronomical Union, Pluto was officially positioned as a dwarf planet in 2006.
Dwarf planets, or "dwarf planets", are between planets and asteroids in volume, revolve around stars, and have enough mass to overcome the gravity of solids to achieve hydrostatic equilibrium (nearly spherical) shape. They do not empty other celestial bodies in their orbits and are not satellites.
Five, Pluto actually found aliens?
After astrologist Rickman magnified the image, a new hole was found, also near the shadow area on the back. For this discovery, conspiracy theorists pointed out that NASA cut off the rest and turned it into a dark part. The image is not complete. There are other things near the hole of Pluto, such as a metal not found on earth or an alien base, which were disposed of.
But we have not seen aliens so far, and this speculation has no basis.
Vi. what is the inside story of Pluto's delisting?
1. Pluto is relatively small, with a diameter of only 2360 kilometers, which is only two-thirds of the diameter of the moon.
2. Pluto was once Neptune's "satellite". Some researchers found an orbital resonance - there is an optimal gravitational point in the orbit between Pluto and Neptune. This orbital resonance can avoid the two planets getting too close to each other.
3. Pluto's surface is covered with a large amount of ice. On the whole, it is composed of ice and water. Two thirds are rocks and one third are composed of ice and water. It can be said that it is a planet composed of ice and water and is not suitable for human habitation.
4. Pluto's orbit is about 4.8 billion kilometers away from the sun, and its surface has been in a dark state without light.
Pluto's atmosphere contains more carbon monoxide and methane than Pluto's atmosphere, but Pluto's atmosphere is thinner than Pluto's.