Why Pluto went from Planet to Dwarf Planet

  • Published: 05 April 2014
  • Why has Pluto has gone from being a planet to a dwarf planet? This video explains why as well as the definition of planets and dwarf planets, a includes details about the dwarf planets in our solar system. The change came about when in 2005 Eris, an object with similar dimensions but around 25% more mass than Pluto, was discovered in a similar orbit to Pluto, in what's now called the Kuiper Belt. In 2006, the International Astronomical Union created firm definitions for planets and dwarf planets. A similar thing happened in the 1800s when between the orbits of Mars and Jupiter was discovered Ceres, Juno, Vesta and Pallas. They were then called planets until many more objects were discovered in the same orbit and they were all demoted to asteroids and the Asteroid Belt. Now Pluto, Eris, Ceres, Makemake and Huamea are all classified as dwarf planets.

    To check if Pluto is still a Dwarf Planet go to:

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    New Years in the Solar System or How long Planets take to Orbit the Sun (1280x720)

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    Solar Energy - Nuclear Fusion in the Sun

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    Some sun and planet images courtesy of NASA.

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  • Science and Technology Science and Technology

Comments • 282

  • Roberto Peixoto Veras
    Roberto Peixoto Veras  3 weeks back

    Pluto's diameter is 2.368 km and Eris' diameter is 2.366 km

    • Francisco Santoyo
      Francisco Santoyo  4 weeks back

      You whiny losers crying that "Pluto is a planet, there are still 9 planets", SHUT THE FUCK UP. The "dwarf planet" classification just proves that our vision of the solar system is still far from being completed or accurate; and that it is more complex and mysterious than we ever thought of. Go read about CERES, it went from being a planet to an asteroid, and I didn't see any of you complaining about that; and thanks to the dwarf planet category it recovered part of its lost dignity. Get over "the 9 planets" bullshit you learnt in pre-school, you idiots.

      • FaZe Legand Ocks
        FaZe Legand Ocks  4 weeks back

        Pluto is such a good planet WHY DID THEY MAKE IT A DWARF PLANET

        • Francisco Santoyo
          Francisco Santoyo  4 weeks back

          Because the dwarf planet category enrichens our vision of our cosmic neighborhood. Go read about Ceres, and you'll see Pluto had it easier.

      • Jim Inverness
        Jim Inverness  2 months back

        Pluto is not no longer a planet. The IAU's 3rd criterion is stupid and nonsensical.

        • marvette wilson
          marvette wilson  2 months back

          do things on black holes

          • Still Cringey
            Still Cringey  2 months back

            Pluto is still a planet in my opinion

            • SCOREFIVE
              SCOREFIVE  3 months back

              pluto is a planet!!!! pluto cant convert that easy :D

              • Tayo Bradshaw
                Tayo Bradshaw  3 months back


                • Rasmus gaming
                  Rasmus gaming  3 months back

                  Pluto is biggest dwarf planet but eris is 27% more massive than pluto.

                  • Bored Af
                    Bored Af  2 months back

                    You're confused kid massive and biggest mean the same thing.. Eris is the largest one

                • Mercy-jo Mills
                  Mercy-jo Mills  3 months back

                  I say Pluto is a planet because it only got changed to a name called a dwarf planet so please try to speak to NASA it is my favourite PLANET by the way did you know that in billions and trillions of years the sun is not going to be a star it will grow closer to mercury then go really small and go to a dwarf planet called the white dwarf and at the moment the sun can fit each planet 600 times each in side of it if you tryed so ha I no mutch more about planets than you do haha haha

                  • Erin Brown
                    Erin Brown  3 months back

                    WHAT ABOUT Charon the dwarf planet

                    • RimstarOrg
                      RimstarOrg   3 months back

                      Oops... here's a link https://en.wikipedia.org/wiki/Charon_(moon)#Classification

                    • RimstarOrg
                      RimstarOrg   3 months back

                      I hadn't realized Charon was even being considered as a dwarf planet until you mentioned it but it looks like it isn't according to the IAU.

                    • Mercy-jo Mills
                      Mercy-jo Mills  3 months back

                      There is no dwarf planet called charon

                  • Alexandrite Pearl
                    Alexandrite Pearl  4 months back

                    Poor pluto i wish your a planet

                    • MarkYuri PH
                      MarkYuri PH  4 months back

                      i was born when the pluto is a planet

                      • gaming and animation/only animation

                        Pluto it's and will be a planet

                        • Senja Langit Gili
                          Senja Langit Gili  4 months back

                          plutos revenge video is coming soon join to wach it

                          • Jaskirat Kingra - Sir Isaac Brock PS (1417)

                            me:Hey pluto!why are you not a planet anymore
                            pluto:ugh not that question again!*Pluto cry's*
                            me:aww poor Pluto i wish i can do something
                            *Pluto crys more*
                            me*getting evil*:i will ask NASA to make Pluto a plane or else i will kill emt*i ask NASA *
                            NASA:NO! sorry
                            me:hmmm or i will kill you!
                            NASA:ok ok
                            NASA:Pluto is now known as a planet!
                            (this is all a fake story)

                            • Connor Roberts
                              Connor Roberts  5 months back

                              I miss pluto

                              • Michelle Freis
                                Michelle Freis  5 months back

                                neptine is rude just becase she is a planet dosent mean she owns evrybody

                                • mrkinla
                                  mrkinla  6 months back

                                  It took me a few videos to understand the "clearing the neighborhood". At first I thought it meant "escaping", but I see now they mean absorbing what's around it or repelling it. Thank you for the clarification!

                                  • 한사코일àhšłÿ ťübèŕ

                                    Pluto​is​cute okay

                                    • BeepBeepImASheep237 BeepBeepImASheep237

                                      clearing the neighborhood is pretty hard for dwarf planets, but pluto is not a planet anymore.

                                      • NoahJKPlays
                                        NoahJKPlays  7 months back

                                        NO YOUR NOT A PLANET!

                                        • *_OceanaKaye_* Gachas
                                          *_OceanaKaye_* Gachas  7 months back

                                          guys Pluto isn't a really planet now!
                                          (sorry for bad English)

                                          Pluto is a dog now!!!

                                        • Don Thursby
                                          Don Thursby  8 months back

                                          Hey, by definition, Neptune isn't a planet either, having failed to clear it's orbit. Now we are down to 7. BTW, the IAU is comprised of morons.

                                          • Bone Breaker
                                            Bone Breaker  8 months back

                                            When pluto is still in the solar system..it is 9th Coldest planet than the neptune

                                            • Irfan Halimi
                                              Irfan Halimi  8 months back

                                              There's no real scientific evidence that proves that Pluto orbits around the sun. Astronomers state that it takes Pluto 248 years to orbit around the sun. And we've only being observing Pluto for 88 years to date.

                                            • Dano1947
                                              Dano1947  8 months back

                                              The asteroid belt could have been a planet that was struck and reduced in size do to impact. Does the asteroid belt have enough matter that this may have been the case? We know venus, mars and uranus were struck.

                                              • Dano1947
                                                Dano1947  8 months back

                                                A dwarf planet is still a planet but don't call it a dwarf, it's a size challenged planet

                                                • Dano1947
                                                  Dano1947  8 months back

                                                  A big ball of ice, maybe a moon of one of the gas giants that broke away.

                                                  • ajeetnegi Negi
                                                    ajeetnegi Negi  8 months back

                                                    Posts elation is small pelation

                                                    • Collin Reynolds
                                                      Collin Reynolds  8 months back

                                                      Pluto is was a planet

                                                      • Dr. Vijayalakshmi
                                                        Dr. Vijayalakshmi  8 months back

                                                        Ganymede and titan are new planets

                                                        • Jillian Goldberg
                                                          Jillian Goldberg  9 months back

                                                          Pluto is a planet now but it's still a dwarf planet

                                                          • Space Explorer
                                                            Space Explorer  9 months back

                                                            There are three more dwarf planets

                                                            • Senbis
                                                              Senbis  10 months back

                                                              100% real!

                                                              • A wild Crash Bandicoot Appeared

                                                                Actually Pluto is the leader of the dwarf planets!
                                                                Now I know Pluto isn’t the biggest dwarf planet but it started this!
                                                                It’s was the planet the orbited the sun BY Neptune so technically Pluto creates its own system like the sun owns the solar system though the6 don’t orbit Pluto Pluto has a belt which is weaker than a system but it’s not someth8ng any other planet has!

                                                                • Benjamin
                                                                  Benjamin  10 months back

                                                                  Brown's classification system is incredibly problematic, and needs to be completely revised. Another issue with his methodology is that from his vague descriptions Earth can be disqualified and demoted from planet status because of the Lagrangian points and the asteroids we share our own orbit with. Brown is smart and has made many discoveries, but he really let his own personal ambition get the best of him on this issue. Demoting Pluto because there are objects far smaller than it that are also beyond Neptune is an absolutely ridiculous notion.

                                                                  • Mario and FNAF fan 991777 Youtube

                                                                    he's back

                                                                    • Posty
                                                                      Posty  11 months back

                                                                      Am I first cause every time I comment I see my self on the top

                                                                      • Posty
                                                                        Posty  10 months back

                                                                        Okey Thx

                                                                      • calista -
                                                                        calista -  10 months back

                                                                        JJ Garing im a noob no

                                                                      • Posty
                                                                        Posty  11 months back

                                                                        Pls tell meh

                                                                    • Posty
                                                                      Posty  11 months back


                                                                      pLUtO Is A pLanEt!?m?!!!!!!!!!!!

                                                                      • edgeeffect
                                                                        edgeeffect  11 months back

                                                                        The Nomenclature Committee of the IAU's definition suits 19th Century astronomers but it's nonsense to a 21st century space explorer. It should be. 1. Has sufficient gravity to make it round 2. Has a solid surface. Much more useful... and it's been specially formulated to annoy the Nomenclature Committee as Jupiter, Saturn, Uranus and Neptune are no longer planets but Pluto is. ;)

                                                                        • Kagiso Ignatius
                                                                          Kagiso Ignatius  11 months back

                                                                          we love the video hope you make more 😀😊

                                                                          • deivid puki
                                                                            deivid puki  12 months back

                                                                            Where is de moon

                                                                            • Walleye Slayer
                                                                              Walleye Slayer  12 months back

                                                                              With this logic, shouldn’t mars be declassified to a dwarf planet? It is smaller then those around the asteroid belt...

                                                                              • RimstarOrg
                                                                                RimstarOrg   12 months back

                                                                                Mars isn't in the asteroid belt. The asteroid belt is between Mars' and Jupiter's orbits. So Mars' orbit is relatively clean of asteroids.
                                                                                From: https://en.wikipedia.org/wiki/Asteroid_belt
                                                                                "The asteroid belt is the circumstellar disc in the Solar System located roughly between the orbits of the planets Mars and Jupiter."

                                                                            • Sujit Ghosh
                                                                              Sujit Ghosh  1 years back

                                                                              Thanks so much! This really helped me. I subscribed!

                                                                              • RimstarOrg
                                                                                RimstarOrg   1 years back

                                                                                I'm glad I could help! And welcome!

                                                                            • Chrstphre Campbell
                                                                              Chrstphre Campbell  1 years back

                                                                              The real reason that Pluto was demoted was because it was becoming clear that there were lots and lots of new planets out there waiting to be discovered, and that ASStronomers just wanted to 'Simplify' things, the same way that Police Officers want to 'simplify' their testimony in court.

                                                                              • Chrstphre Campbell
                                                                                Chrstphre Campbell  1 years back

                                                                                This is why i hate science and equate astronomy with astrology.

                                                                                • super gamer Bro dude
                                                                                  super gamer Bro dude  1 years back

                                                                                  If they add pluto Back as a planet they Should call it like a rocky planet. Yes or no