Astronomers drive teachers crazy. If the reader is older than 20, he would study at school that the solar system has nine planets. Your teens have learned that you have only eight, since Pluto dropped from the list 13 years ago. But the younger brothers of the latter are likely to return to the old solar system of nine. Not because Pluto returns, God protects us – that the "dwarf planet" always seems deader and buried – but because it all points to the fact that there is another planet in our border, much larger and very distant, so far away that we were left unnoticed. Up to now Welcome, dear teachers, on planet 9. Read on things the recent discoveries that night-sky scientists have come to believe in his existence. There is a world beyond the Kuiper belt.
Question for Trivial: Did Kuiper discover the Kuiper belt? This was in fact a hypothesis developed by the Irish astronomer Kenneth Edgeworth in 1943, but it is true that his Dutch counterpart Gerard Kuiper, who eight years later gave the idea a solid theoretical basis. As Gabriel García-Márquez said, it is a real exclusivity not to give it before, but to give it better. Kuiper concluded that, according to physico-mathematical models of the formation of the solar system, the outer planets (Uran, Neptune and now missing Pluto) should have left many remains to be in the slower and still external orbit.
Everything points to the fact that there is another planet on our frontier that we have not noticed so far
And right now, the Kuiper belt, today we know, consists of hundreds of millions of ice objects that turn around the Sun very close to the plane of the Solar System (ecliptic), and there they remained during the formation of Neptune, 4.5 billion years ago, where they are visiting us the most common comets; Comet is just one of those ice rock that suddenly experience a change in its orbit and approaches us to the inhabitants of the inner planets. When approaching the Sun, their ice evaporates and forms a familiar tail that characterizes these objects. And they are intact witnesses of the origin of our corner of the universe.
Pluto is no longer the farthest planet in the solar system, but one of those bodies in the Kuiper belt, and even the largest we know. Pluton's vulgarity in that neighborhood is just the reason why the International Astronomical Union was degraded to the painful category of "dwarf planet" in 2006. But it seems very likely that we still have the ninth planet, though far bigger than Pluto and very, very distant, so far that we will still need ten years to observe it. The imagination goes beyond knowledge, as Einstein said or should have said.