Why Pluto is Not a Planet? Simple Reasons for Kids to Understand Why Pluto is no Longer Considered a Planet

Our Solar System is a strange yet intense and beautiful part of the universe, which we admire and are curious about. We asked for reasons why Pluto is not a planet back in 2006. But we didn’t find the answer because it might haven’t made a pennyworth of difference to our work. Just like the fictional detective Sherlock Holmes once said about the Copernican Theory and the composition of our solar system, “you say that we go round the sun. If we went round the moon it would not make a pennyworth of difference to me or to my work”.

Sherlock Holmes was the imagination of Sir Arthur Conan Doyle, so it doesn’t make a difference to us if the smartest fictional detective cares or not, but we do. So, we should know why Pluto is not a planet. The study materials were rewritten to give reasons to the conjecture why or why not Pluto is a planet. So, to give your kids a precise answer on why is Pluto no longer considered a planet, go through this blog.

Discovery of Planet X

 

Yes, you read correctly, “Planet X” was the name given to Pluto by the astronomer Percival Lowell. Lowell began an expensive expedition in search of a possible ninth planet in the year 1906. He began the search at his Lowell Observatory in Flagstaff, Arizona, established in 1894. The possible ninth planet was termed “Planet X” by Percival Lowell. Alongside Percival Lowell, another important person in the expedition of Planet X was the planet predictor William Pickering.

By 1909, Lowell and Pickering had suggested some coordinates for Planet X. Unknowingly, Planet X has been captured in many photos since 1909, beginning with the first photo captured unknowingly on 20 August 1909 at the Yerkes Observatory. There are sixteen such pre-discovery photographs of Planet X, captured before its discovery in 1930 by the astronomer Clyde Tombaugh with Pickering’s contribution. On 19 March 1915, Lowell Observatory had captured two faint images of Planet X, but they didn’t recognise it. Unfortunately, Percival Lowell didn’t know about this before he died in 1916.

Resume

The search for Planet X resumed in the year 1929 when the expedition was handed over to Clyde Tombaugh. His work at the Lowell Observatory was to take a pair of photographs two weeks apart, image the night sky systematically, and examine if any object in the photographs has changed position. He used a blink comparator machine to see the difference on the plates by changing the views between plates and creating a blinking illusion.

Finally, on 18 February 1930, Clyde Tombaugh observed a significant movement of an object on the photographic plates of 23 and 29 January 1930. The news of the discovery of Planet X was announced by Lowell Observatory on 13 March 1930, which marked the birth anniversary of Percival Lowell, and also William Herschel’s discovery of Uranus in 1781. Around 1000 names were poured in as suggestions for the name of Planet X, but an 11-year-old girl named Venetia Burney from Oxford, England suggested the name Pluto. And Planet X was officially named Pluto on 24 March 1930.

Downgrade to Dwarf Planet

In 2006, the International Astronomical Union (IAU) downgraded Pluto from the status of the ninth planet from the Sun to one of the five dwarf planets. The IAU didn’t expect that their proposal of demotion of Pluto to a dwarf planet would be met with such outrage. The information in the textbooks had to be rewritten. It confused many kids too at that time because they studied about nine planets, and suddenly there’s only eight now.

The proposal of IAU at the General Assembly of 2006 was a defining move for the classification of the solar system. Pluto was demoted because, before the year 2006, there wasn’t any specific definition for the word planet. But in the year IAU defined the word planet, and for a celestial body to be considered as a planet, it must qualify for three things:

#1. It should orbit the Sun.

#2. It should have enough gravity to make it into a spherical shape.

#3. It should be huge enough that its gravity clears similar-sized objects from its orbit around the Sun.

Pluto was a celestial body, but it wasn’t able to clear the orbit, as it wasn’t that huge to exert gravity and clear the path. So it had to be demoted from the status of the ninth planet.

What is a Dwarf Planet?

There are five celestial bodies counted as dwarf planets in our solar system: Pluto, Ceres, Haumea, Eris and Makemake. The IAU has defined the three points mentioned above to define a planet, and the dwarf planets only meet two out of the three criteria. It states that a dwarf planet is a celestial body that orbits the Sun in our solar system. It also has a large gravitational force to give it a spherical shape and isn’t controlled by mechanical forces. But it doesn’t meet the criteria of clearing the neighbour area from debris in its orbit.

So the orbital path of a dwarf planet is not clear like the orbital path of planet Earth. It is said that there may be thousands of dwarf planets orbiting our solar system beyond Neptune, which are yet to be discovered. The four dwarf planets Pluto, Haumea, Eris, and Makemake, are located in the Kuiper Belt in our solar system, and the Ceres dwarf planet is located in the main asteroid belt.

Conclusion

This blog deftly answers why Pluto is not a planet for kids. These reasons why Pluto is not a planet are enough to make your kid understand why it is a dwarf planet. Such astronomical dynamics can be a bit tough for your kid, so you can opt for the best learning experience at the Real School Of Montessori. The innovative teaching methods of the Real School Of Montessori mix enjoyment with education making it a memorable experience for kids. You can check their website for more information.