Pluto, an icy planet that is far away and unfamiliar to us, has long been controversial. Once Pluto, it was included in the nine planets of the solar system, and in 2006, the International Astronomical Union downgraded it to a "dwarf planet".
Since then, the solar system has only 8 "traditional" members left, namely Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.
So why was Pluto ruthlessly kicked out of the nine planets of the solar system? Walk into the beginning and end of the event together, learn about this former ninth planet, and unveil the "mystery" of Pluto!
How was Pluto discovered?
The discovery of Pluto is quite dramatic, and it has to start with Uranus. After the discovery of Uranus in 1781, astronomers found that its orbit seemed to be somewhat contrary to the laws of planetary motion, but could not explain why this phenomenon occurred.
Based on Newton's theory of gravitational attraction, astronomers speculate that if there is interference from an unknown planet beyond Uranus, then the orbital motion anomaly can be explained. So they began to search for another unknown planet.
Shockingly, neptune was really discovered in 1846, which confirmed the speculation of astronomers, which can be described as a sensation!
After Neptune was "calculated", astronomers began to study its orbit, found some abnormalities, and speculated that neptune should have another planet in addition to the gravitational interference of Uranus, according to Newtonian mechanics.
Astronomers began the search for the so-called ninth mysterious planet. This time it didn't go so well, and decades later, the existence of a ninth planet was still not found.
At the end of the 19th century, a big landlord who liked astronomy in the United States established the Lowell Observatory and began to try to search for the ninth planet, until his death in 1916, without achieving substantial gains. In fact, he had already taken two pictures of Pluto, and because it was too blurry, he didn't notice it at all.
Until February 18, 1930, a 24-year-old young man, Tombaugh, confirmed the existence of Pluto, and the scientific community boiled over, and after so many years of painstaking searching, finally had results.
The naming of "Pluto"
After Pluto was discovered, it called for names around the world. One day in March 1930, an 11-year-old British girl, Bernie, was having breakfast with grandpa Madden when she heard the news that grandpa was reading the Times about the naming of the new planet.
Bernie grew up very interested in ancient mythology, astronomy also studied, she knew that all the stars in the solar system are named after the gods of Roman mythology, so she proposed that the newly discovered planets be named after Pluto, the god of Roman mythology.
Grandpa thought it was good, so he reported his name, but he didn't expect to be hired in the end, and the little girl was rewarded with 5 pounds.
Pluto's status is controversial
When Pluto was first discovered, human beings had a very limited understanding of the planet, thinking that it was larger than Earth, so it was logical to list Pluto as the ninth largest planet in the solar system.
With the continuous updating of astronomical observation technology, the study of Pluto and other stars has become more and more in-depth, and the controversy over the status of Pluto has also continued to emerge.
Pluto's mass was grossly miscalculated. Astronomers found that Pluto's mass was actually smaller than the moon, only one-fifth of the moon, and they thought it was larger than the earth, but they did not expect that even the moon was inferior.
Pluto's orbit is too bizarre. While the orbits of the other planets in the Solar System are all in the same plane, Pluto is oblique, forming a 17-degree angle to the ecliptic plane and having an orbit that intersects neptune.
Some astronomers have proposed to kick Pluto out of the ninth planet of the solar system, thinking that it is not worthy of being a large planet at all, but some astronomers believe that "Pluto is the ninth planet" has long been written into textbooks and has been widely circulated, and it is not appropriate to kick out the list of planets at this time.
In 2006, Pluto was ruthlessly kicked out of the nine planets
The kicking of Pluto out of the list of nine planets in the solar system was often mentioned, and the controversy continued until the discovery of the planet Xì in 2005, which became the fuse for Pluto to be kicked out of the nine planets, and can also be said to be the last straw that crushed the status of Pluto.
As a Kuiper Belt object, the volume of Eris is larger than Pluto, in addition to Pluto, astronomers have also discovered Ornithos, Genesis, Sedna and other celestial bodies, which is a bit embarrassing, is it necessary to include them all in the solar system planets? In this case, the solar system planetary family is too chaotic.
Thus, in 2006, the International Astronomical Union redefined the planet, and Pluto was kicked out of the nine planets of the solar system and reduced to a dwarf planet, but for reason, it was not unjust at all.
Demystify Pluto
In January 2006, NASA launched New Horizons to Pluto for exploration.
Before New Horizons, human beings knew very little about Pluto, it was 6 billion kilometers away from the sun, even with the powerful Hubble Space Telescope, the information that could be detected was very limited, and only a small spot could be photographed.
However, one thing is frightening, the surface of Pluto is unusually cold, and it is speculated that what will it be like on a dark and cold planet at minus 230 ° C.
In July 2015, New Horizons sent back data that did not disappoint astronomers, and the mystery of Pluto was gradually unveiled.
New Horizons took the clearest picture in Pluto's history, and looked closely at the white area like a heart, and scientists explained that it was actually a huge ice field, known as the heart of Pluto.
For the first time, human beings have seen the face of Pluto, which is shocking! Scientists have found that Pluto's sky is blue, which is very close to the blue of Earth. Pluto's surface has mountains, cliffs, glaciers, etc., and the landform is diverse.
There is a complex chemical composition on Pluto, and astronomers have even speculated that there may be a pre-life origin process below the surface.
New Horizons brought back a lot of information, the analysis has not been completed until now, and there may be more discoveries about Pluto in the future.
The article comes from the Internet, and if you have any ideas, you can discuss them together in the comment area. [Rose]