Is there a 13th planet discovered in the solar system?
Question:
Answer:
No. There have been a number of objects discovered recently in the outer solar system, including one which appears to be larger than Pluto. But unless something about the size of Neptune is found (which is possible) none of these are likely to gain official planet status.
In fact, in many respects Pluto should be "demoted," although that is not going to happen.
There isn't a real scientific definition of where the boundry is between a planet and, say, a moon, or a Kuiper object. For most objects it's clear what to call them, but for others the classification is ambigious. The reason being, of course, that our classifications are (somewhat) arbitrary and the solar system is composed of a continuum of objects of different sizes, in different orbits, etc.
Pluto was called a planet when it was discovered because a 9th planet was expected. Percival Lowell spent a long time looking for such a planet which he predicted from orbital irregularities he calculated with Neptune and Uranus. But he never found what he was looking for. Clyde Tombaugh, a couple of years later, resumed the search and eventually discovered Pluto. However, Pluto is much too small and in the wrong place to be Lowell's suspected planet. Lowell was probably just wrong in his calculations.
Because a 9th planet was expected and because in 1930 little could be told of Pluto's physical characteristics, I don't think anyone seriously doubted whether or not it should be classified as a planet. It seemed obvious, at the time, that it was.
In the 1950s and 1960s astronmers began to postulate that comets orginated from a vast pool of objects in the extreme distant regions of the solar system. This lead to the hypothesis of the Oort cloud, and the "closer" Kuiper belt (that being 50 - 100 AU from the Sun).
It wasn't until the 1990s that a lot of Kuiper-esque objects were actually discovered. (I hedge on the classification, because some objects similar in diamter, etc., have been found inside the orbit of Pluto.)
If in 1930 Clyde Tombaugh had an inkling of something like a Kuiper belt he probably would not have assumed that Pluto was a planet. If Pluto was discovered today it also would (probably) not be considered a planet.
So basically, if we could re-do history Pluto would be "demoted." On the other hand, there have been generations of kids who learned the whole 9 planets bit. Because of the the International Astronomical Union - the international organization in charge of naming things - has *officially* declared Pluto a planet. A link to their announcement is below.
I suspect - and I am taking an educated guess - that the new objects in the outer solar system, even though slighly larger than Pluto - won't get "official" planet status.
Of course the reality is more complex, and nature doesn't always fit neatly into human classification schemes.
Her name is "Janet"
No. There is 12 planets, Mercury to Pluto.
nope
13th one?
I thought we have only found nine planets right now.
Next planet?
Probably and most likely.
Just guessing.
More Questions & Answers...