But it has been 13 years since Pluto suffered a severe decline in status – officially called Pluto's Demon Day.
Pluto was released in 2006 when the International Astronomical Union (IAU) created a new definition for the planets and decided that Pluto was out of place.
But this did not solve the question of fans of distant Pluto.
The dwarf planet was also known for being the only open planet in the United States.
It was spotted in 1930 by astronomer Clyde Tombo at the Lowell Observatory in Arizona (named after America otherwise) astronomer Percival Lowell who believed that the Martians were digging the channels found on the surface of this planet).
The story behind Pluto's name is also known.
The newly discovered planet, about 3 billion miles in the sun, will be known as the "King of the Kuiper Belt."
But how the mighty fell.
And then there were eight
The UIA reclassified it as a dwarf planet, also calling it a "trans-neptune object", which provoked outrage from students, small enthusiasts of the planet and the Internet in
For many space lovers, Pluto's decline felt suddenly. But in the academic world of astronomy, it was a process that began only decades after the discovery of the dwarf planet.
In 1992, astronomers at the observatory of the University of Hawaii at Mauna Kea discovered a small ice celestial body a little farther from the orbit of Neptune. Named the Kuiper Belt Object of the 1992 QBI, the speculation has sparked speculation that Pluto is just one of many planetary objects in the Kuiper Belt.
New horizons resume old debate
But the debate about Pluto's condition is raging.
According to NASA, data gathered by the flying horizon of New Horizons "clearly indicate that Pluto and its moons are far more sophisticated than suspected," prompting space enthusiasts to wonder whether he will regain his status on the planet.
Even the chief investigator of the New Horizons spacecraft, planetary scientist Alan Stern, disagreed with the IAU and claimed that Pluto was downgraded simply by its distance from the sun .
"In fact, if you put the Earth where Pluto is, it will be excluded! "Stern told CNN in 2015.
A year earlier, the Harvard-Smithsonian Center for Astrophysics also entered the debate. After a panel discussion on the definition of a planet, they let the audience vote and, of course, the crowd supported Pluto
"The IAU definition will state that the main object of planetary science – the planet, should to be defined based on thread  Metzger and his team looked at studies worth over 200 years and found only one study that uses the orbital clearing standard, which
"This is a slimy definition," Metzger added. "They did not say what they meant by clearing their orbit. If you take this literally, there are no planets because no planet clears its orbit. "
Too cool for school
When Pluto was downgraded, it triggered a wave of textbook reprints to guarantee that the new millennium students will be taught. Pluto is a dwarf planet.
But it may still be the coolest (non) planet to learn – literally.
In fact, Pluto is so cool that its temperature is about 400 degrees Fahrenheit below freezing and becomes even colder as it orbits farther from the sun. Pluto is so far from the sun that sunlight is as bright as the full moon on Earth, and from the surface of Pluto, the sun just looks like a bright star.
"The complexity of the Pluto system – from its geology to the satellite system to its atmosphere – is beyond our broadest imagination," Stern said in a NASA statement. "Everywhere we turn, there are new mysteries."