Elementary Science


Author Post
Victoria Chanda Victoria Chanda 2280 Points

I am a student teacher and we were recently going over the planets. The resources we were instructed to use were 2012 documents. In the documents it stated that Pluto was the ninth planet from the sun. I thought Pluto was changed to a "dwarf planet". Has anyone else found this in science books that they use or was the document I used just faulty? Would the paper say that pluto is a planet so we don't confuse students more?

Betty Paulsell Betty Paulsell 48560 Points

The New Horizons mission to Pluto and the discovery of more than one moon around Pluto helps the discussion to continue in the world of astronomy whether Pluto is a planet or not. The astronomers have debated back and forth since the discovery of Pluto and will probably go on for many more years. So you see papers pro and con on the subject. As for putting in a paper that Pluto is a planet in order to not confuse students, I doubt that is the real reason. Many things in science do not have a right or wrong answer, because many things in science are still under study and will stay that way until science advances enough to give a definitive answer.

Here is some background information about how Pluto was designated a 'dwarf planet' Science 101: Why is Pluto no longer a planet? On August 24, 2006, the International Astronomical Union (IAU) decided that Pluto was no longer a planet, but rather a "dwarf planet". Our understanding of the solar system has not undergone any radical changes, our understanding of Pluto did not change, nor did any great theories in astronomy undergo revision. Whatever the reasoning for the reclassification, it has left quite a few scientists upset and many science educators have hailed this as a major change in scientific understanding. [url=] Ceres and Pluto: Dwarf Planets as a New Way of Thinking about an Old Solar System[/url] In 2006, the International Astronomical Union defined the terms "planet" and "dwarf planet." The IAU's decision created an opportunity for students to understand the solar system better by considering the definitions of planet, dwarf planet and asteroid. New discoveries in the solar system require a change in the language used to discuss it. The activity uses direct vocabulary instruction to help students learn these new definitions. This was a 'hot topic' in classrooms a few years ago.

Maureen Stover Maureen Stover 41035 Points

Hi Victoria,

What a great question! I know I've also heard some rumblings that the discovery of an additional satellite orbiting Pluto may bring it back into it's former status as a planet. Here's some information on Pluto, and it's dwarf planet status, that I found on the IAU Pluto page. There's some really interesting information on the history of Pluto and why the IAU reclassified Pluto as a dwarf planet. I've also attached a collection of NSTA resources that I found related to Pluto. I've taken the opportunity of Pluto's changing status to remind my kids of how dynamic the study of science is and how we are constantly learning new things through exploration and experimentation. Good luck with everything!


Pluto, the 9th Planet? Collection (6 items)
External Resource: Ceres and Pluto: Dwarf Planets as a New Way of Thinking about an Old Solar System
- External Resource
Science 101: Why is Pluto no longer a planet?
- Journal Article
Scope on the Skies: And then there were eight
- Journal Article
Angela Alcantara Angela Alcantara 2940 Points

Victoria, If you search the learning center there is an article called Science 101: why is pluto no longer a plant, that explains what happened to Pluto. I was also very confuse with all the information about Pluto no longer being a plant. Every time I would ask someone if Pluto was a plant or not, I would get different answers. This article help me get a better understanding, along with articles that I placed in my collection that I could share with you . Angie Alcantara

The Solar System Collection (7 items)
Science 101: Why is Pluto no longer a planet?
- Journal Article
Sizing Up the Solar System
- Journal Article
Solar System: A Look at the Planets
- Science Object
Michael Leslie Michael Leslie 2110 Points

Some schools haven't updated their textbooks probably due to lack of funds but I think it should be taught with the most current information. I got a lot of help from the sci-packs and sci-guides from the topics of space science. It would be cool if students got textbooks in a reader so things could be updated more regularly with the most current information. I can understand how it would be hard for some people being taught that Pluto was a planet and now is not.

Denise Karratti Denise Karratti 820 Points

The last I heard, Pluto was dethroned as a planet. This would mean those fun little mnemonic devices used to remember the order of the planets will have to be adjusted. Below is a link an article National Geographic put out back in 2006.

Patricia Reid Patricia Reid 1850 Points

The latest is Pluto is no longer a planet and I catch myself teaching it as a planet. At that time, I remember and I tell my students it is no longer a planet, but a dwarf planet. I can see where there will be discussions on going about it's classification and Pluto's status may change. The books in my room on planets were bought at least 5 years ago and they are wrong now. It is a teaching moment to say how science is changing all the time with more information.

Pamela Auburn Pamela Auburn 68555 Points

You might enjoy reading Niel DeGrasse Tyson's Book on the Pluto debate entitled the Pluto Files. There is also a NOva program on this Understand the arguments that lead to the reclassification of Pluto is a great opportunity to discuss the process of science.

Patricia Reid Patricia Reid 1850 Points

Pamela, Thanks, I will check both out.

Janelle Buttera Janelle Buttera 465 Points

Pluto was my favorite planet growing up. I sometime see older textbook at different schools I observe at, and they still have it as a planet in the books. Of course the students are quick to tell you it is not a planet anymore though.

James Johnson James Johnson 95308 Points

Hi Victoria, I took a graduate course at Penn State recently that used the following text and I felt is was really a good read. Book Description Publication Date: November 24, 2008 A Note from the Author: On August 24, 2006, at the 26th General Assembly of the International Astronomical Union (IAU) in Prague, by a majority vote of only the 424 members present, the IAU (an organization of over 10,000 members) passed a resolution defining planet in such a way as to exclude Pluto and established a new class of objects in the solar system to be called "dwarf planets," which was deliberately designed to include Pluto. With the discovery of Eris (2003 UB313)--an outer solar system object thought to be both slightly larger than Pluto and twice as far from the Sun--astronomers have again been thrown into an age-old debate about what is and what is not a planet. One of many sizeable hunks of rock and ice in the Kuiper Belt, Eris has resisted easy classification and inspired much controversy over the definition of planethood. But, Pluto itself has been subject to controversy since its discovery in 1930, and questions over its status linger. Is it a planet? What exactly is a planet? Is Pluto a Planet? tells the story of how the meaning of the word "planet" has changed from antiquity to the present day, as new objects in our solar system have been discovered. In lively, thoroughly accessible prose, David Weintraub provides the historical, philosophical, and astronomical background that allows us to decide for ourselves whether Pluto is indeed a planet. The number of possible planets has ranged widely over the centuries, from five to seventeen. This book makes sense of it all--from the ancient Greeks' observation that some stars wander while others don't; to Copernicus, who made Earth a planet but rejected the Sun and the Moon; to the discoveries of comets, Uranus, Ceres, the asteroid belt, Neptune, Pluto, centaurs, the Kuiper Belt and Eris, and extrasolar planets. Weaving the history of our thinking about planets and cosmology into a single, remarkable story, Is Pluto a Planet? is for all those who seek a fuller understanding of the science surrounding both Pluto and the provocative recent discoveries in our outer solar system.

Jennifer Glass Jennifer Webber 770 Points

When covering planets in 6th grade last year, I found it was a hot topic among my students- so I had my students complete a debate on the topic. They were given time to research their sides, prepare arguments and rebuttals, and prepare for the debate. It went smoothly in the classroom and I plan to use it again this year. There are many resources for different Pluto debate guidelines, I believe the one I used was called "the great Pluto debate" but I'll have to look at my resources when I am back at school.

Cris DeWolf Cris DeWolf 11925 Points

Mike Brown is one of the astronomers who played an active role in the demotion of Pluto. Here is a link to his book on Amazon - How I Killed Pluto and Why it Had it Coming: It's a good read. This decision was made by the International Astronomical Union, for valid reasons. Even some asteroids have satellites. This alone is not a good reason to restore Pluto's "planethood".

Julie Tonnsen Julie Tonnsen 1590 Points

Like a lot of other people have said, turn the fact the some say Pluto is a planet and some say it is not. Have the kids debate about what they think and have them weigh the evidence given. They are more likely to remember something they were able to give their input. Side note: I believe Pluto is a "dwarf planet" and has a satellite called Cheron. Here's brief information on the debate: There has recently been considerable controversy about the classification of Pluto. It was classified as the ninth planet shortly after its discovery and remained so for 75 years. But on 2006 Aug 24 the IAU decided on a new definition of "planet" which does not include Pluto. Pluto is now classified as a "dwarf planet", a class distinct from "planet". While this may be controversial at first (and certainly causes confusion for the name of this website) it is my hope that this ends the essentially empty debate about Pluto's status so that we can get on with the real science of figuring out its physical nature and history. Pluto has been assigned number 134340 in the minor planet catalog. Read more about Pluto l Pluto facts, pictures and information. by

Cris DeWolf Cris DeWolf 11925 Points

Hi Julie- The debate is a great idea. Also, Pluto has quite a few satellites - 5 so far. Who knows what the New Horizons mission will find both on the remainder of its flight out to Pluto, and beyond.

Natalie Hepting Natalie Hepting 610 Points

Hello everyone, we just finished our science unit on planets. We had to adapt the materials regarding Pluto. We also included a discussion of Pluto changing its status as a planet. My students actually enjoyed calling it a dwarf planet. However, when we built our solar system we included Pluto with a small dot labeling it dwarf. I took the opportunity to include a lesson on how technology allows us to learn more about science and our surrounding. Additionally, we included a discussion on science’s contribution to technology change and progression (importance of science). Natalie

Jonelle Renti Cruz Jonelle Renti Cruz 615 Points

Hi there. I understand your confusion. I just found out today that 9 planets became 11 planets and then increased to 13 planets. You've probably already seen the Science Object: "Solar System: A Look at the Planets." It's a great view of the individual planets and data about each one, but it doesn't clarify the classification of Pluto. It's very dated. This article I found has more information if you're interested: Your text to link here...

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