Earth & Sky

Factsheet available: is Pluto a planet?

Boyds Mill Press and astronomer Ken Croswell have made available a free fact sheet that may be particularly useful for teachers. It’s called “Is Pluto a planet?” It provides a clear summing up of the arguments for and against planethood for Pluto.

THE FACTSHEET is here. It’s a PDF file and it may take a minute or two to fully download.

Thought the issue had been settled, you say?

In fact, there’s still a movement among astronomers to call Pluto a planet, despite a vote in August of 2006 by the International Astronomical Union, which for many decades has claimed the right to name and define astronomical objects.

Now many astronomers – including Ken Croswell – are choosing to defy the IAU’s new planet definition.

3 Comments for Factsheet available: is Pluto a planet?

1. 1

   Jan 3, 12:21 AM #

   Magenta says:

   Thank you very much for the link. The Pluto fact sheet is an excellent and succinct summary of the main arguments for and against Pluto’s planethood. It’s also nice to see lots of FACTS given—facts that contradict some things I’ve read in the press. For example, the January 2007 issue of Astronomy magazine has a letter that incorrectly claims astronomers have discovered “bigger objects” than Pluto—note the plural. In fact, as the “Is Pluto a Planet?” fact sheet notes, only ONE object has been found that’s larger than Pluto. That’s Eris, which is three times farther from the Sun than Pluto. Clearly, if Pluto is a planet, so is Eris.

   Any teacher who’s mystified by the mess should definitely get the fact sheet and print it out for students. You can’t beat the price: it’s free!

2. 2

   Jan 13, 09:03 AM #

   kennedy says:

   unbelieve able i was expecting something bigger

3. Jan 13, 11:32 AM #

   Deborah Byrd says:

   Did you see the actual factsheet? It’s here. It’s a pdf file and might take a minute or so to download.

   Best,
   Deborah