Saturday, September 09, 2006

Pluto - Dwarf Planet

Dear students,

You may have read about the recent announcement by the International Astronomical Union (IAU) to re-categorise Pluto as a dwarf planet and wondered how this information could impact your learning of the solar system in the science textbook. While you are not required to either name the planets or describe their relative positions, the current textbooks provide additional information about the planets.

The debate on the status of Pluto is an excellent opportunity for us to appreciate the role of evidence in supporting scientific theories and how advances in science continually re-define what constitutes scientific knowledge.

Some of the key points which you may find useful:

Pluto was first discovered by astronomer Clyde Tombaugh in 1930 through multiple observations of the planetary system. Advances in telescope technology and further discoveries of planetary bodies in the 21st century started the debate on the status of Pluto as a planet. The IAU on 24 Aug 06 decided to adopt a set of new rules for a planet: "a celestial body that is in orbit around the sun, has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a nearly round shape, and has cleared the neighbourhood around its orbit." In essence, the oblong orbit of Pluto that goes into Neptune’s elliptical orbital path disqualifies Pluto as one of the planets in the solar system.

You may find the following information on Pluto useful:

1. International Astronomical Union and the resolution on the definition of a planet
http://www.cnn.com/2006/TECH/space/08/24/pluto.ap/index.html

3. It's official--Pluto's out
http://news.com.com/Images+Its+official--Plutos+out/2300-11397_3-6106240.html?tag=st.bp.story

4. Rest In peace, Pluto (Sunday Times, 27 August 2006)

5. Pluto's demotion not a cause for classroom panic

2 comments:

Anonymous said...

Dear Mdm Tan,
I am about to ask you some Ques. in Practic paper 1.2B that you given us on friday.Pls help me as I am confused!!!Plus pls tell me what what is your MSN ,so that i can ask you directly
Regards,
siyu

me said...

Hi Siyu,

you can get me on msn by adding this email: etanyl@hotmail.com